How strange. I've also got s voice disabled but still notice lag.
I think it has to do with how many apps I have open, as if there's only 1 or 2 it opens almost instantly. When it's bogged down with 20+ there's a noticeable lag.
It's not a deal breaker or anything but it is mildly annoying if I'm in a hurry to do anything.
I don't think it has anything to do with that, cause mine runs fast regardless of how many open apps. I think it's an animation bug, probably something to do with ram cache.