About 3 weeks on sulbutiamine, 5 on piracetam. I haven't gotten any quantitative data. Before I started, I thought I ought to get in the habit of using dual N-back and Anki and some other tests so I'd have a baseline, but didn't really have the energy and motivation to set those up and do them. Once I realized that was stopping me from trying nootropics at all, I dropped that idea and settled for subjective impressions, collected informally. I have some subjective feeling data recorded in my private diary, but it pretty much just duplicates what I posted in comments.

Piracetam and sulbutiamine have pretty much orthogonal effects. If you're already taking a supplement with lots of thiamine, then sulbutiamine will have a smaller effect than it would otherwise since they are analogues of the same molecule, but I think there's a limit to how much thiamine can cross the blood-brain barrier which doesn't apply to sulbutiamine so you may still get some effect.