They say "New features for 2001: Until this year, the Miller Cycle engine was available only on the top-of-the-line 'S' model, but it is now standard on all Millenias. The base 170 horsepower 2.5 litre V6 engine has been discontinued. "
Again, that's in Canada.
They also say "This engine has been rated more than once as one of Ward's Auto Reports '10 Best Engines', a prestigious award given annually by a U.S. trade publication". Not bad.
When it comes to interior space - I am 6'3 and do fit comfortably in the Millenia, do not fit in 626 (center console keeps my right leg at very odd angle). In this case I guess size does not matter sure I have less room around me than in my (already sold) 1995 Passat GLX, but I bought a Chevy Venture van for the wife and kids, and Millenia for myself!
I test drove Acura TL (including S), VW Passat (maintenance is $$$$$$$ after 2 yrs), Infiniti J30, Maxima, ... etc. - and for me only the Lexus GS300 was better than Millenia, but also out of my price range ($40K+). Of course BMWs are better - if money (to buy AND maintain in the long run) is no object.
Anyway, I'm really enjoying my little new toy...