Horizon 2 is colorful, vibrant and clean, and looks best at speed off-road, on night-time rain-slicked roads, and at dusk or dawn with its long shadows and gleaming sun shining just beyond the crest of the hill and behind the trees. But the roads and buildings are overly simple and smooth in shape, the off-road trails are flat in detail (a regression from the graphics in Horizon 1's expansion), and there is a good amount of pop-in on cars ahead of you on the road. Something about those simple roads and buildings still screams last gen to me, even though there have been a ton of improvements.
DriveClub has a duller palette, but the lighting is on an altogether higher tier than anything in Horizon. That lighting, with those car models (immaculate both outside and in), and the much greater detail in track geometry and textures reaches much, much greater heights than Horizon.
They are two different styles - and where I have loved the artistry on the vistas in Horizon, DriveClub has honestly floored me on many occasions. I just feel far more immersed in DC than I ever have in Horizon, even though Horizon is a beautiful place to be. Play some of DC's point to point tracks without a hud and if you're not seeing something above and beyond what any console game has graced us with then we just have completely different eyes.