Lookin good! That's a nasty dent on your bottom tube. Wowz.
I'm still shopping for a proper bmx bike. Hopefully in the next month I'll have one.... My piece of junk works with little tricks for now... My tires are 2.125 also. Just some cheap Bells I bought from Kmart when it was going out of business. Were your previous tires fatter than 2.1? I think tread has something to do with how sticky they feel too....