I'm having the exact same problem. I just recently came back to the S3 from the Note 2 and I have to say I think that Jelly Bean for the Note 2 is far superior to Jelly Bean for the S3. The samsung keyboard on my Note 2 worked flawlessly and it is shotty as hell on the S3. I've tried a few different keyboards such as Swiftkey, Swype, ICS keyboard and JB keyboard and they are all very laggy and buggy on this phone after the JB update. Really wishing I had kept my Note 2 right about now.