OK, my first .177 Disco/pump was bought at Impact Air Gun's closeout sale. cant complain at all since he discounted it significantly. I tore that thing apart 4 times to do trigger tunes, polish pellet inlet, moved barrell bands around countless times (I have a TKO muzzle brake on it). Got to the point where I could get a subset of decent groups at 25 yards, but some of them were still a bit variable (not bad and still accuate). Well I got my Disco from Mac 1 today (again in .177). All I did was transfer the scope (Legend), a 2nd O-ring barrel band, and my TKO brake. After zeroing in, BAM, tight groups. Not necessariliy better than the best groups I obtained with my 1st disco, but most of them are that tight. No monkeying around. I't is better than my stock one even after I tinkered with it quite a bit. Liturally 45 minutes after I got it I could tell it was better!
I do have a comment on the power adjuster. It is very tight. I tried to move it and could not, not even a little bit. I get a set of pliers but decided not to force it. I will call Tim tomorrow and ask.