FH2's wet roads just don't look right. Maybe it's a shader related thing, I find DC easily topping it.
The wet environments in Driveclub really look a cut above anything you can find in FH2 (I haven't played the expansion yet), that's one area in which I hope Playground implements some significant improvements.
On the other hand, I
really dislike how rain and snow stick to the screen regardless of your chosen perspective. It ruins the good job accomplished elsewhere. I also don't entirely like how the effects look in the cockpit view. While I appreciate the fluid physics on the windshield, the effect looks overdone, like there's some oil mixed with that water. The droplets are also too big, and too pronounced. At the same time, FH2's windshield effects look too subdued, even during the most violent rainstorms (again, I haven't touched the expansion yet so I can't comment on any potential improvements). My ideal would be somewhere in-between Driveclub's and FH2's implementations.
Another thing I dislike about Driveclub is the starfield effect while driving at night, especially when snowing. That should be
much more subtle, with perhaps more vignetting going on. FH2 is once again too subdued in that regard, although in this case I'd actually take that insufficiently pronounced effect over Driveclub's showing off.
(EDIT: Actually, scratch that, watching the comparison video, the night driving effect in FH2 looks
exactly how I'd want it to look, it's just lacking in the interaction with the windshield.)
But yeah, Driveclub looks leagues ahead overall, mostly thanks to the superb work on the environments.