I am glad to hear this. I have been thinking of upgrading to 5.1.1 to possible fix a GarageBand issue. I'd have to de-jailbreak and then upgrade.
There are times where iOS 5.0.1 takes a bit to respond to touch signals. Apparently it is not as bad as the iOS 5.1.1.
I have noticed that some of the time I am getting touch lag is when I am getting a pop-up on the screen saying I have new mail, or whatever. This is caused in my case because I have wifi at my house, but connect to my ISP via a dialup connection. When the iPad is having trouble talking with the email server it seems to glitch.
Sent from my iPad using iPF - Peace