I have, for another month or three, a 2005 A6 with virtually every option offered in that year.

I have driven both the A5 and S5 at my dealer -- the MMI seems virtually identical to the one in my A6. In fact the entire look of the dash is apparently an updated A6 C6 design.

This means, I like it, a lot.

The MMI controls the Navigation, AM/FM/Sirius/CD, and Telephone sub-systems. Additionally, there are controls called CAR, INFO and one for your "address book" (which, if you have both the bluetooth phone and the Nav systems, allows you to enter "Office" as a destination and a phone number, etc.

Additionally, the Nav, Sound and Tele are controlled by voice, simply by pressing a button on the steering wheel and saying: "Navigation" then "Navigate to office" or "Telephone" then "Call office" (or reciting up to 7 digits of a phone number at once.) When controlling the audio, you say "Radio" or "CD" -- if you have preprogrammed stations into your radio, you simply say "Radio" then "Play the vault" or "Play classical pops" or whatever you have previously saved with a voice tag. Help is always available by simply saying "Help MMI" or "Help Radio," etc.

To control the climate system, there are two temp controls, separate from the MMI cluster and pushbuttons that can be synchronized: then you crank the temp to 68 and both readouts AND the MMI display the number 68. If you have the system set on Auto (I have never NOT had mine on anything else but auto, it works so well, front and rear) everything is figurered out for you, blower speeds (12 of them) the mixture of cool to heated air, etc. -- you can call up addtional functions to override the auto functions and you can set the center vent to a temp preference from cold to hot.

Some of the CAR functions on the MMI include daytime running lights, the power lock preferences, coming home and getting in (lighting) functions and interior ambient lighting. You can check your oil life and level, set the wiperblades for service and change the surround sound functions, clock, date, etc.

The volume control for the radio seems to fall naturally at your hand, either on the steering wheel or on the console -- you don't need to take your hands off the wheel if you don't want to, you also may find the console volume knob without looking, it just is "exactly" where you'd put it if you had designed the thing.

The pushbutton start requires you to rest your foot on the brake and press and release the start button, and you're off.

The cruise control is especially cool if you are driving, for instance, in West Virginia near the Ohio, Penn, WVA tristate area -- you can set the cruise to your desired speed and, unlike many Cruise Controls, still being put on new cars, even today, maitains the speed perfectly -- it brakes on the steep downhill grades and downshifts and accelerates on the steep uphill grades.

The first time the thing applied the brakes I was really impressed, since I had just been in my wife's, then new, BMW and my inlaws new Chrysler 300 and a Cadillac DTS -- the Audi was the only one that both accelerated and applied the brakes (and the brake lights come on, too.)

Anyway, the MMI is easy to use, rarely requires one too many steps (rarely, NOT never) and does not require as many window drill downs or drill ups as iDrive.

I do prefer the Infiniti's and Acura's voice control to Audi's but that, overall, would not make me jump ship.

Oh yea, the Audi backup camera displays in the MMI screen and it works well showing you the result of your wheel turns.