Grand Theft Auto IV is a good game but it's too demanding. Although I managed to make Assassin's Creed, Batman Arkham City and other demanding games to go smooth without sacrificing quality I can't do the same with GTA IV.

I've tried the Razor1911 version updated to v1.0.7.0 and the whole game is slow and stuttering.

From what I see there are other versions like Reloaded or Skidrow, plus several repacks?
Does anyone knows which is the best version?
Should I trust repack versions? And which one?

Some help please.