Yes it has been ridiculously slow for me. Even running searches has been slow. There were a couple of bloggers I follow complaining about it too. There was a problem in one of the data centers that only effected 2% of users supposedly Google fixed it but I'm still seeing slowness issues.
If I delete an email and go to close the tab 3 seconds later. I get the 'if you navigate away from you this page you may lose work' error from Firefox. It shouldn't take but a split second to complete the task of deleting an email.
Yeah, I noticed deleted emails having an issue too. They will pick up the trash label but the original label also sticks so I end up with deleted emails hanging out under my labels for a few extra minutes.
I don't use my Gmail/Google Apps anywhere near as heavily as you guys apparently do, so I hate to say this, but, for whatever reason, my Gmail is lightning fast.