autocomplop[1] is easier to install, but not as sophisticated. I just installed it to see if I like the idea of having completions pop up automatically.
I forked autocomplpop a while back to fix a couple issues and make it easier to add new language support. Never noticed a speed issue. I always preferred acp vs the others due to its simplicity.
Aye. I remember having problems with autocomplop though when I had a rather large amounts of text open at once; YouCompleteMe seems like an improvement in that regard though. Handled