I play most PC games without modding, especially because I'm on Linux. I've compared and read about the improvements, and to its just minimal changes. Only the first game got huge improvements, but I'm more interested into playing 2 only. And as someone playing lot of old games and emulate old systems, its totally fine with me. I even played GTA 4 (last year and this) without modding on PC, but still have to finish it.