I am on my 20th hour and save file over just over 5mb and things are starting to feel a bit laggy it started when I faught a dragon in low res (no scales populated, just low Res brown).
I notice a few hangs when I enter a city etc, is this how it all starts?
That same dragon issue occured to me at around the same mark - ie 20 hours. It looked very strange and took a long time to give up the soul. It also started to get
very laggy in Whiterun.
I noticed that two Alik'r warriors, who were obviously a failed cleanup from an earlier quest, had started lurking inside Whiterun's gate... I decided to break my roleplay and murder them, since it annoyed me so much. Lo and behold, Whiterun became playable again.
I'm now around 35-40 hours (put the game on the shelf until they sort out the magic resistance) and haven't had any further issues, apart from a couple of crashes. Framerate has generally been fine. Time will tell though, I'm sure.
Quest bugs were what brought me to the forum - I've hit so many of them it's a joke, and I'm convinced some of them are contributing factors to the lag issues other people are facing. Unfinished scripts hogging memory has been a problem since Morrowind. Very annoying to know Bethesda won't even start looking at these until January. How big a holiday do these guys need? I get 3 days off, tops.