Product review (4 stars): Strong, silent type
Good points:
My previous disposal froze up, and couldn't be broken loose again.  When you turned it on, it just made a quiet humming noise.  This KitchenAid disposal makes the same amount of noise as that when it is working.  Very quiet.  They have a 1HP model that is supposed to be even quieter, but I think that is unnecessary.  Even when chewing on two cups of ice, the amount of noise is just slightly louder than the running water from the sink.  3/4 horsepower is plenty for a residential kitchen as well.  The only possible reason for going with the larger 1HP model is that it supposedly has an extra grinding stage (3 versus 2 in this one) that grinds up things smaller.  If you had a septic tank instead of sewer service, that might be worth considering.

Otherwise, this monster is such an upgrade over the standard builder grade disposals and the common Insinkerator "Badger" models that you'll almost certainly be happy if you're coming from one of those.  The internals of this model are made by Insinkerator, and are the same as the Evolution Essential.  I bought it because the Kitchen Aid version wound up being cheaper.

Also nice is that the rubber guard that fills the drain hole is easily removable,  That is very nice, and not something that is common.  You can just pull it out, clean it without having to worry about sticking your hand down in the disposal, and put it back.

Bad points:
This unit does not include the pieces you need to connect it electrically.  So be sure to save the power cord off your old disposal.  The necessary parts (strain relief, wire nuts, power cable) can be had pretty easily/inexpensively at the hardware store of your choice, but be aware that you'll need to purchase them.

Things to consider:
This disposal is physically big,  There is a good chance you'll wind up with less space under your sink than you had before, so keep that in mind.  The extra size may mean you have to cut some of your existing plumbing because it would be too long.  Big grinding chambers, noise insulation and 3/4 horsepower motors need a big package.

The dishwasher inlet hole is optional and sealed.  If you're using it, be sure you don't forget to punch out the plastic piece sealing it.  Its in the manual, but you might overlook it.

The install was pretty easy.  The sum total of my previous similar experience was replacing the drain in the kitchen sink (not all the plumbing, just the piece in the sink).