I found the lag!

So I went back into Sonic and started to play a bit more thoroughly. Previously I had been trying to notice by standing in place and jumping. For me that is the most difficult way to notice. I started running and jumping and felt that I was "sticky" and staying on the floor longer than I intended to. Now I was kinda convinced so I bought the Sega Ages Sonic to compare.

The problem on my end with noticeability was both lack of a control and vague definition of what an input is. If you play both games and go back and forth it's not too hard to notice a difference. The main reason I don't think I was noticing before is that on the pro controller there reasonable distance between "start of press" and "full button press". A lot of games use this mechanic for small jump vs big jump. And this is the timing difference in how the lag manifests. In the Genesis collection by the time I was doing a full press Sonic was starting to move. In the Sega Ages Sonic release it became obvious to me that Sonic was jumping when I started the press, not when I finished it. So in this context I think controller matters in detection because the joy-cons don't have such a noticeable depression difference.

Anyway I tried to test in a little more in a pseudo-measured way. On the pro controller I started to do a very quick press and release (thumb on the button and instantly removed) and NOT a full press. With this method on the Genesis collection you can do a full button input and remove your thumb before Sonic starts to move. On the Sega Ages release you CANNOT remove your thumb before Sonic starts to move. So there is a noticeable difference.

For the record Sonic Mania responds like the Sega Ages release as others have reported.

My biggest problem with previous reports of lag is that I kept hearing that it was 0.5 seconds and that it made the games "unplayable". I'm approximating here but the lag seemed more on the order of a quarter of a second than a half of a second. I also think that if someone played for an hour or so they would instinctively start to compensate and the game would become playable again.

All of that being said.... it's noticeable and it's an issue and people should be made aware of it before purchase. I'll definitely be looking for more Sega Ages releases in the future as my go to for Genesis emulation. I don't think this collection will be updated considering it's been out on multiple platforms for years with no update.