The new MDX and RL are not the typical Japanese cars. I have driven them and they are different. Not saying better than BMW, but they have come a long way.
See review by a X5world member here

I've had Acura for the last 10 years. Starting with a 98 4 door Integra GS-R, a 04 TL 6MT w/ nav, and a loaded 05 MDX. Still own them all! I have also had a fare share of BMW in my family, 81 320i, 95 525i, 07 328xi. All sold and left with only the X5 as far as BMW goes.

My X5 parks next to my MDX everynight. The vehicle that I primarily drive is the X5. I have had and still have my fare share of warranty issues, more than all of my Acura's put together. Having said that, I can't think of any other vehicle I'd rather drive on a daily basis than my 4.8is! (and my acura's when BMW doesn't have a loaner for me)