I heard bad things about it so I decided to avoid it. I certainly don't want to pay for it 
I got the free upgrade on my first gaming PC, but had to pay for it on the new one.
I read someone complaining that the game lacks a sensation of speed. I�ve only played for two or three hours, and it certainly doesn�t if you drive in car. I�ve cut the gameplay video with the chase camera replay and to be fair, as driving games go, it feels reasonably quick in that external camera too. Not as manic as in car, granted, but quicker than many driving games. Check out the awesome cars Lieutenant!
A short dash through the countryside.
I�ve still not had a chance to get the wheel set-up, but to be fair Horizon is well designed for stick control, probably the best experience I�ve had with a controller on a driving game. A proper �rubbing is racing� touring car style experience, where you don�t get spun out at the slightest shunt; imperative to the enjoyment of a stick racer.