I have had Honda motorcycles (including several of the turbocharged '82 models) and Honda leads the way in engine design. Variable valves were developed and popularized by Honda as were many engine refinements.
Now onto the Odyssey. This isn't Honda's best product IMO. In fact, the Civic has been the most reliable bullet proof model in Honda's lineup. Still compared to other vans the Odyessy is a good van. I wouldn't worry about the VCM motor. You are likely to feel a shutter now and again, but that's about all. The motor mount is a separate issue and is likely a bad design that Honda either has fixed or will address. I think the weakest component on the Odyssey is the transmission which is simply overworked as the Odyessy is a big heavy vehicle pushing a lot of air at 70 mph.
Of the vans the Sienna might be the most trouble free, but the AWD version is to be avoided. The Odyssey is next in reliability, but I'd make sure to have the trans serviced every 30K miles.