LA Noire was very poorly optimized and the framerate was capped at 30 FPS. Even with the cap, there were often times where it would drop below 30 and changing the detail settings made little to no difference in terms of performance or visuals. Also, the M/KB controls were not well-implemented.
GTA4, like LA Noire, was horribly optimized. Just ran like utter trash and didn't even look very good (the shadows were just as low-res as in the console versions). With modern hardware, you can brute force your way past the lousy optimization but that kind of defeats the whole point of optimizing in the first place.
As for GTA5, I see no reason why it won't eventually make it to PC. Every GTA game (except for that handheld one) has been released on PC. The PC version has always been announced and released long after the console versions since GTA3. GTA5 PC will probably be announced a few months after the console versions are released. Hopefully it's a solid port like MP3 and not GTA4 or LA Noire.