Mine is definitely snappier than ever after applying this update and a giving it a couple of reboots. It doesn't seem to be degrading over time either (I was wondering about this myself, so I've been paying attention).

It's to the point where I'm needing to re-learn my 'swipes' in the UI in order to avoid flying past the items I'm looking for. Definitely an increase in the speed of that action for me.

Another place I'm noticing a dramatic difference is in "All Albums" view in the MP -- pre-update, it was annoyingly laggy to the point that I just stopped using that view (note that I was nit-picking here, it's not like it was busted or anything, just not much fun). Now it's smooth as can be (I'm definitely keeping an eye on this one though).

Moving between windows/apps also seems to be marginally smoother, and the browser has seen an increase in page-loads and link responsiveness as well as others have reported.

Overall, the result has been a noticeable improvement in the way the device 'feels' to use. Very nice