Product review (4 stars): Awesome cooling control!
For installation I'd give this unit a 3 1/2 out of 5  It does fit into a standard 30 inch cutout (good) but the gas inlet is in the far right rear corner of the unit and that interferes with cabinet installation if the unit is offset from the cabinet as in my case.  The NGM805 does also extend under the countertop more than the unit it replaced, so some cabinet surgery was needed to allow the cooktop to sit properly.  The hold-down attachment hardware was not thought through very well and had to be 'modified' to work properly.

Cooking: this unit gets a 5 out of 5 in my book.  Cooking control is AWESOME.  That's the advantage of gas--you have INSTANT & INFINITE control of your cooking and don't have to wait for burners to cool down as on electric cooktops.  The three sizes of burners let you do everything from large pots to warming chocolate and everything in between.  The previous reviewer "Nice Guy" just had never worked with a gas cooktop before, indeed the very things he complained about are discussed in the user's manual ("Don't use a rounded WOK" and "Don't make the flame larger than the pot being used.") The unit doesn't deserve a lower rating because the user was unfamiliar with the physics involved.  This baby cooks GREAT.

In 'chocolate warming mode' the small 5500 BTU burners can be turned down so low that I can't even see that the flame is on (I'm tall), so it's a good thing there's a light on the front panel that lets you know when the burner is on.  Automatic relight works fine in case a burner is blown out.

The grates are very stable, much more so than the unit it replaced, a 22 year-old Kenmore that had grates that slipped out of position when the pot/pan was tilted for stirring or extracting grease. They were a pain to get seated into position again.  With the Bosch I worry no more.

There's more effective cooking area workspace with the Bosch; the 5 burners give you more flexibility than the 4-burner competitors.

Cleanup: I give it 5 out of 5. No seams and rounded corners on the stainless top make cleanup MUCH easier than the old Kenmore unit.  The burners are raised from the stainless top, keeping the burners free of overspills.

Only gripe:  The control knobs stick up above the level of the grates by about a half inch, so you can bump the knob as you take a heavy pot off the cooktop if you don't lift it up.  Fortunately the knobs are metal and not plastic. (A lady in the store when we looked at this unit had to replace her melted platic knobs on a different make because of this problem)  With the metal knobs this shouldn't be a big problem.