I actually played Horizon 2 for the first time at a booth at PAX Aus, and as good as it looks I just couldn't see myself enjoying it all that much. The forced offroad felt really weird, and with no limits to stick to (without penalties a la DC) there's really no refining a particular driving line to improve times... at least in the brief stint I had with it.
It also took far too long to get into anything! The guy before me had just completed that initial Lambo run, so I had to sit through so much convolution... unskippable voiceovers, unskippable cutscenes, little bits of hand-holding at every corner. It was a relief to come back to DC and just push three or four buttons and be in a race.
More power to people who like Horizon 2, if it's anything like H1 it'd be a great exploratory title. But from what I can gather, the RPG element of it takes a strong passenger seat to the driving and pulls emphasis from it somewhat. DC is just pure driving and that's why I adore the hell out of it.
One of the posters above me was spot-on on potential as well. Driveclub feels like it has more room to grow than H2. A monthly DLC pack of 5 cars or whatever is a whole bunch of new cars compared to the ones that already exist... but 10 cars in H2 in addition to the few hundred already there are likely to get lost in the fray and rarely appreciated.
God, I hope this doesn't start some kind of flame war (and I don't intend it to). Hell, if I ever buy a One (I'm sure I will) no doubt I'll be getting FM5 and H2. But with neither seemingly having the focus on pure driving/racing like Driveclub does (as long as they have tuning/liveries in it, I doubt they ever will) I don't think I'll ever favour them.
It's why (up until a month or two ago) I still play(ed) PGR4.
The tracks, the physics, the graphics... they are all top-notch. The only thing I feel the game needs in order to be the best racing game it can be is a larger and more varied car list.
I can only guess, but with Japan being the next location I suspect your wish will be granted