I have a 2007 R320 CDI with around 37k miles; I can compare because my wife drives a 2007 Odyssey Touring.
The R320 is nicer in some ways than the Odyssey but I wouldn't say it's the most reliable vehicle also dollarwise the MB doesn't make sense.
I have often mentally compared the strong points of both vehicles, so here goes.
The R320 rides better, is way quieter, more powerful off the line, much better in heavy rain and snow due to the 4matic and far more unique in terms of not seeing five of them a day. The front seats are far more comfortable and the R-class styling appeals to me a lot more than a boxy minivan.
The diesel gets me 500 mile tankfuls and 27 mpg highway; the Odyssey is around 21-22 mpg highway, tops.
The AC is much better in the MB, and the rear seats are heated (a $700 option in the 2007.)
Bad points are depreciation, and the trunk latch is finicky, sometimes not opening at all. The R has six cup-holders to the Honda's 15+.
MB offers a weather radio, bigger sunroof, and stickered at 64K compared to the Honda at 40K with nav, the only option. The MB has 20K in options.
Braking is the one Mercedes strong point which would make me come back for more even in spite of all the problems. The electrohydraulic brakes in my R do work much much MUCH better than the Honda brakes.
None of the Mercedes SUV's have hood ornaments, a major reason I might go back to a real car with hood ornament (E or S class)...
The rear seats in the Odyssey are more comfortable, at least in my older daughter's opinion, who does a lot of seat time in both.
My youngest can kick the screens mounted to the seat backs of the R320, but cannot reach the ceiling mounted screen of the Odyssey.
The local MB dealer is not as good as the local Honda dealer, sorry.
Better coffee at the MB dealer, but more revisits to the local profit center because "we ordered the wrong part" for recalls and other problem areas, like repeat visits for a strong smell of diesel fuel ("we didn't smell anything"). Finally a service bulletin for a weeping fuel line or some-such helped them "find it."
The Odyssey is roomier, has a very high quality interior which seems better thought out than the compromised space of the R-class, handles like a "Civic with a minivan body" (salesman line which is actually true), and has better resale value. I am told that a 4x8 sheet of plywood will fit in an Odyssey; I have not tried this yet.
The pricey and hard ride of the PAX system tires that Honda used for a few years does not make for happy owners, forcing Honda to revert to standard tires. Honda imho has a much better sound system and more ergonomic nav system.
Maybe this is why the Odyssey is more popular.
I still love my R, but it's a niche market in terms of resale.
But from my reliability issues I ask now ... does anyone want to by my R next year when the warranty runs out?
Considering offers over 40k
