I agree. I used to play a drum beat game with my daughter and son-in-law, who are both professional musicians, and they could hit beats within a 10ms window, while I struggled to get under 100ms.

But 100ms seems like a reasonable upper limit for autocomplete to me.

PS: My son-in-law is a professional drummer and can't play Rush YYZ on Rock Band (just had to include this tidbit cause it'll piss him off)