Product review (5 stars): Overall my experience has been great
I've had this convection microwave for 4 years & haven't had a problem with it.  Overall my experience with it has been great.

KEYPAD VS. DIAL
My biggest hesitation with choosing this model was that it has the dial knob instead of a keypad.  I thought it might be hard to use / interact with the dial, being so accustomed to using keypad microwaves; but it is simple and intuitive.

Everybody seems to use it a little bit differently.  I always hit the 30 second plus button to get the microwave started, and then rotate the dial up or down to add or subtract time in 5 second intervals.  Or I hit the 30 second plus button a couple times, say two times for one minute cooking.  My wife seems to hit the time cook button and then rotate the dial up to her desired cook time, and then push start button, or push/click in the knob.  My friend that has the same microwave says he can't live without the reheat w/ sensor single push-button option.

CONVECTION COOKING
I knew I needed a microwave with convection option.  My parents have had this option on their microwaves for the past 20 years, so I can appreciate its usefulness.  Any chance I can get away with not having to heat up the whole regular kitchen oven, I take it.  The convection within the smaller microwave-size box cooks the same as the regular oven, but it really doesn't heat up the house and probably uses half the power.  The regular oven throws off heat like crazy.  This one you never even notice it.

Have you ever cooked for a crowd of people, and said to yourself 'I just wish I had an additional rack or two in my oven for that extra space' or 'I need to run my oven at two different temperatures' -- that is what a convection microwave is for.

I didn't know why the unit came with two racks inside.  One rack is about half way up, and the other sits inside only about 2-inches above the turn-table.  I thought the bottom rack was pretty useless, bc. why wouldn't you just put the food right on the rotating turn-table instead of on a rack 2-inches high?  I realized later that when you bake, you are always supposed to put the food on a rack so that there is hot air circulation underneath the food.  When you microwave food, you can put the food right on the turn-table; but when you bake, you should use a rack.  Baking with a rack assures that the bottom layer cooks at the same rate as the upper layer, by making sure there is air-flow underneath the food.  [Side Note: you CAN leave the rack(s) in the oven while microwaving even though they are metal - there's no issue with sparking or anything like that which is normally associated with putting metal in a microwave.]

There are fans inside that operate while baking, so unlike your regular oven, there is a low fan noise while baking.  But, I guess that is the definition of "convection": baking with air circulation to increase the heat transfer of the air-to-food.  The convection cook times are identical to the ones when you use your regular oven.  Convection makes for a uniform cooking method because air is circulated, which eliminates hot spots right next to the heating element.

The convection oven / baking feature on this model works best (in my experience) when operating at 375F or less.  It takes a little while longer to heat up to temperatures higher than that because it isn't as powerful as a regular oven.  It can reach 450F, though it takes some time.

P.S. I still can't figure out how the "roast" button operates differently than the "bake" button - is the operation of the microwave different by pushing one button or the other??

MICROWAVE COOKING
The microwave power could be stronger.  If you are "that guy" that needs your reheated mac & cheese to be done in 1 minute rather than 1 minute and 15 seconds, then maybe this isn't the one for you.  That being said, I find the microwave cooking of this unit to be exceptionally uniform in temperature (without hot spots) compared to other microwaves.

This microwave is powered with 1000W.  The most powerful microwaves aren't going to do much better than 1250 Watts (because of the electrical power limitations in residential USA), at best (just search Amazon).  So the difference in cooking time between this microwave and the most powerful ones is going to be 15 seconds longer in the microwave per minute.  This has never been any issue for me.

My guess is that all convection microwaves are going to have less microwave power than microwave-only ovens because convection microwaves not only has to have the electrical power consumption of microwaving, but also has to have the power consumption of a convection bake oven too, so you can't have both powered electrically and stay under the USA 115V UL / ETL electrical power codes & regulations.  This model not only has 1000W of microwave power, it also has 1500W of convection baking power, for example.  So, when all considered; you'll probably have to decide whether you want a really powerful microwave, or a microwave that is also capable of convection baking because there may not be both.  (sorry for the tangent)

OVER-THE-RANGE VENT FAN
The over-the-range vent fan is fine.  When my contractors did my kitchen, they commented on how strong the vent fan was from this over the range microwave and they were very impressed.  Mine vents outside, but you can recirculate it back into your kitchen after being filtered internally if you don't have the capacity to run the duct work outside.  You do need to perform routine maintenance in order to maintain vent fan performance - there are two screens / metal filters that need to be washed.  It is not a consumable part, so nobody can complain about GE gouging them by jacking up the price of consumable parts.  They are actually pretty robust metal screens.  The screens are easily removable - they require no tools to remove.  They are washable in the dishwasher.  This is all in the manual.

The fan noise does seem very loud to me, but there are 3 different settings.  The high and medium fan speeds are loud, but the low fan speed is reasonable decibel level.

APPEARANCE
The look of this microwave really pulled together our kitchen design.  We bought a house and instantly knew we had to re-do the kitchen.  There was a new black stove and dishwasher that came with the house, but we bought said microwave and a refrigerator too.  We (more-so my wife) wanted to modern look of stainless appliances.  The part-stainless of this microwave matched our new refrigerator, and the part-black of this microwave matched the appliances that came with the house.  Very sharp.

LIGHTS
I just found out today that this unit has two lights - one to light up the area underneath the range microwave (i.e. your stove cooktop area) and one inside of the microwave so you can watch your food cook with all of your other lights in the house turned off.  The light inside of my microwave must have gone out a long time ago and I never noticed.

There is a very small, but plenty bright halogen lamp that acts as the range light.  My halogen light exploded on me.  It was running super bright for a ~2 weeks (like burning bright like the sun) and then it popped and glass parts shattered within the plastic housing.  I don't know what was up with that.  It was simple to replace.  I got the replacement bulb here on Amazon; $8 plus $5 for shipping.  ( ... )  One screw, put the bulb in, done.

The range light has two brightness settings: regular lighting and night light.  The night light is a nice feature that you can leave on until the kids come home, or leave on all night if you have company over who are not familiar with your house.

I will try to give the inside light replacement a shot, and then try to come back and give you an update but my review as it stands today is that the convection microwave works great without a light inside.  D. Abrams posted a comment within the B. Short "nurse4life" review with this link instructing how to swap the light bulb without needing to take down the microwave (thank you D. Abrams): <...>

CONCLUSION
I don't have a complaint about my experience with this microwave.
-Great reliability after 4-years.
-Sleek design.
-Great mix of performance and options.

Recommendations for improvements: lower fan noise