Basically everything runs smooth. On the title screen you select which Silent Hill you want to play then it takes you to the main menu of the game. Nothing has changed, there are no added extras, just the menus you'd normally see on the PS2 versions. Silent Hill 2 had little problems and was the least glitched of the two. There was no noticeable lag and minimal amount of animation issues. The fog was decreased slightly, but it was nothing too bothersome. The game looked pretty similar to the original, not sure it benefited from being rendered in HD too much. Theres a nice option to chose if you want the original or new voice actors for the cutscenes, which is always a good thing. The new voice actors aren't really as memorable or as suitable as the original. I hated Eddy's new voice actor, and Jame's new voice actor wasn't as memorable for me either. Anyways, everything seemed to run smooth, I beat the game with no problems and very minimal differences between the original and this HD version.
Now Silent Hill 3. This is the game many people stated suffered the most from the problems that plagued the game prepatch. There were a very small graphic and animation glitches that seemed pretty standard, and nothing too noticeable. There was no lag or main problems. However I do have one main complaint. During a few cutscenes, the voices don't match with the animations. The sound is a bit delayed when the characters open their mouths, making the cutscenes a bit annoying and frustrating to watch. Plus, no option for original voice actors. I was not fond of a lot of the voice actors in this version. I don't like Heather's voice actor, or Claudia's all that much. Leonards and Douglas' are the only two I really thought were done well. These are really my only complaints about 3. Other than no option for original voice actors and this voice animation glitch, the game ran near identical to the original, with a few small glitches that are mildly noticeable.
So overall, I'm pretty satisfied with this collection, but it does suffer a few glitches that make it inferior to the original versions. Hopefully theres a patch than can finally fix these glitches in the future. If you already own the original versions of both these games, I recommend you keep these, as this game makes no noticeable improvements, even in the graphic field. However, if you don't own these, or you want trophies, or simply don't feel like having to undust your PS2, then get this. Its worth the bargain, and they are pretty identical to the originals that they won't mess with the playing experience. I just wish they would have also included Silent Hill 4, maybe we can get a second collection consisting of 4, origins, and shattered memories in the future.