I decided to buy the RX 350 after considering the new MDX. I picked up my new RX last Friday. this is my first post to the group and I'm afraid it's gonna be kinda long (what a way to get acquainted)
Contrary to what someone else said, I found that you get more for your money with the RX than the MDX. The Acura dealers I spoke to were sticking to MSRP on the MDX, I was able to negotiate lower than MSRP on my RX. Besides that, several things are dealer accessories on the MDX that were included on my RX. Some of those include body side molding ($495) cargo cover ($195), roof rails ($495), wheel locks ($115). Acura charged for the items plus installation so the items cost a lot more than they were listed for on Acura's website. When I was done adding up the all accessories I'd need it was well over $2K, not including the items below. I agree with the person that said fake wood on an MDX is inexcusable. Also the backup camera on the Lexus is in color, while the Acrua is b&w.
I got a set of all season mats for the Lexus, front and back seat for $99. Acura wanted $195, $60 of which was installation! Acura wants $991 to put on a tow hitch, Lexus is doing mine for $500. Acura has to replace the rear bumper to put on the tow hitch. The tow hitch wasn't even available for months after the car was released, it's like it was an afterthought and not considered in the initial design.
Let's talk about the power lift gate which is included on the RX. The only way to get it on the MDX is to buy the entertainment package which adds over $2K to the cost. I think that was a blunder on Acura's part. They took too long to add the power lift gate and then they packaged it to make the cost exorbitant.
I read reviews of the Lexus and Acura on http://auto.consumerguide.com. For fuel economy it said of the Acura: "Test MDX averaged 15.5 mpg. Acura recommends premium-grade fuel", and of the Lexus: "Test AWD RX 350 averaged 19.1 mpg overall, 21.9 mpg in mostly highway driving".
Based on all that, I decided there's more value in the Lexus than the Acura.
I liked the look of the MDX when i first saw it, but the more I looked at it the less I liked the front-end. I don't care for the grill (my DH says it looks too much like a PT Cruiser) and the big black plastic front bumper. I prefer the MDX dash to the Lexus. I did think the MDX was comfortable and liked the handling of the car, but again the sport handling is another $2K addition. I'm perfectly happy with the comfort and handling of my new RX.
I've had the Acura navigation system in my old car (Honda Accord) for 2 years and I also have a Denso nav system in my other car ('91 MR2) so I'm very familiar with both of them. The Denso in my other car is an after market system and does not have the lockout, it's fully functional while driving. Between the two, the Denso is the better system. The screens are more intuitive and I can find my POI's much faster on the Denso than the Honda system. I like the audible cue (two chimes) when you reach a turning point, Honda doesn't have that. The Denso touch screen is better than the Acura joystick for the navigation. The joystick navigation on the Acura is not intuitive. Lots of times you need to turn the joystick like a knob when you'd expect to push it left/right/up/down. You'd have to go try it to know what I mean. I'm sure you'd get used to it, but touch screen is easier and faster. I still think the Honda is one of the best nav systems, I just prefer the Denso. The lockout on the Lexus is an issue, I don't think they should do that. I'll have to see how much it bothers me and if someone figures out a hack.
My experience with the Honda voice recognition system was that 98% of the time it did NOT properly recognize the voice command when given correctly. So that also differs from what other people are saying. We used to use it as a joke, issue a command and wait to see what it'd do instead of what we wanted. So far, my Lexus voice recognition has worked perfectly; for the 2 1/2 days I've had it :-)
I'm very happy I decided on the RX.