Suffice it to say, Acura's engineers spent a lot of time improving the 2003 MDX, and while the improvements may be very subtle to the eye, they are easily experienced.
The overall demeanor of the MDX is now slightly more relaxed than its predecessor, with a noticeably smoother ride, less road noise, and smoother operation of the transmission. The extra 20hp is less noticeable however, no doubt due to the curb weight which nudges 4500 lbs in our test configuration.
The overall driving experience is quite similar to driving a TL, only in a taller, heavier package. The gauge cluster and much of the trim is quite similar. With the MDX Touring Package you get a few extra luxury touches that aren't found on the TL, such as rain sensing windshield wipers and automatic headlights. One thing I will note right here is that unless the headlights are in the "auto" position, they will not automatically turn off when you lock the car, as I discovered the first morning after getting the MDX. In other Acuras (and some Hondas), you simply leave the light switch in the "On" position and the lights shut off shortly after you pull the key from the ignition and lock up. In the MDX, this is not the case. They stay on until you remember to switch them off or your battery drains. If you set the switch in the "Auto" position, there's no problem.
The 3.5L is more than adequate for typical duty around town. The heavily revised 5-speed automatic transmission works in concert with the drive-by-wire throttle to optimize shift quality and its logic has been carefully programmed so you do not experience "hunting", nor do you have to wait for a kickdown if you need an extra bit of juice. On the open road, a "Type A" personality may find the gearing of 5th (and even 4th) to be a little too tall, resulting in a few extra kickdowns if you need to pass slower moving traffic, and the effect is exaggerated on hilly terrain. I took the MDX on a fairly long (~800 miles total) road trip and found that it can be a little thirsty (averaging about 17-18mpg) if you drive with a heavy right foot. On flat roads the numbers improve by about 1-2 mpg, and if you can live with setting the cruise on 70 mph and leaving it, you'll probably see even better fuel economy. Of course, every time I try to maintain a set speed with the cruise, I always end up getting stuck behind duelling blue hairs who decide to match speeds and roll side by side at 5-under for 20 minutes or so, so that rarely works out unless I'm driving on completely deserted roads. But I digress. Overall, the 3.5L J-series V6 is an excellent powerplant, smooth and refined, but it comes up a little bit short in terms of torque at low revs. You really only notice this deficiency in the upper gears, but with 4500lbs to lug around, it can be noticeable.
The ride and handling are quite good for a "truck"; indeed it's probably preferable to a number of luxury sedans. Through turns, body roll is kept well in check, turn in response is good, and the vehicle is reasonably willing to change directions without the typical cumbersome fell you experience in other SUVs and light trucks. Roadholding limits are modest, yet adequate. On straight sections of asphalt, it cruises smoothly and handles road imperfections quite well, and directional stability is another strong point. 80+mph cruising is no sweat. Noise levels are also kept commendably low, offering a quieter ride than an Odyssey, and almost on par with a TL.
If there's a weak spot in the chassis setup, I would have to point my finger at the brakes. They seem to be not quite up to the task of hauling down this bruiser from freeway speeds. They'll get the job done, but not without occasionaly protest in the form of shuddering or pad fade. Perhaps a simple change in pad material would improve matters, or perhaps the brakes just need to be upsized.
You may have noticed at this point that the VTM-4 system has yet to be mentioned. That's part of the beauty of the system. You will be hard pressed to recognize that it's even operating, as it apportions torque smoothly and seamlessly to any of the 4 wheels. It's refined to the point of near transparency. For the most part, it masks the fact that the MDX is primarily driven through its front wheels. There's not even a hint of torque steer or other nastiness that's typically attributed to high torque FF setups. Acura's engineers claim that the VTM-4 system is capable of proactively sensing wheelspin and engaging the rear drivewheels before any slippage occurs. After playing around a bit with the MDX on wet, dry, and sandy roads, this claim seems believable. The addition of VSA to the MDX for 2003 means that active braking is used to emulate the functionality of a limited slip differential by slowing a slipping wheel and redirecting torque to the opposite drive wheel. Not tested was the "VTM Lock" function, which locks the transfer case, engaging the rear drive wheels (up to a certain speed) to aid in removing oneself from a ditch or other hazardous predicament. The vehicle is said to be engineered for "medium-duty" offroad applications, and I think it's safe to assume that only a very small percentage of MDXs will ever see anything approaching "medium-duty" offroad use.