Stock shifter's crap. No problems with the B&M. If you use true red Loctite, as opposed to the red stuff that claims to be the same as Loctite, the bolts will not back out. And if you apply the RTV sealer to the top of your transmission -- you won't get leaks. Why B&M's instructions tell you to put that stuff on the bottom of the base is beyond me -- because if you don't outline the pattern of the transmission case correctly -- the oil's gonna flow.
That said, the performance of the B&M does leave something to be desired. I used to have a Mustang with a Pro 5.0 shifter -- and it worked just how svede says the GMM works in his car. With the B&M -- finding some gears, particularly 3rd, 5th and 6th -- just isn't precise -- where my old Pro 5.0 was almost like a ratchet -- bang, bang, bang, bang.
Yes, the GMM costs a lot more -- and, from what I've heard, is a total pain in the rearend to install -- but if I wasn't working morning, noon and night -- I'd buy one and replace the B&M in my car. Hope that helps.
Would like to know your thoughts on the CTS-V vs. the GTO. Was going to get a CTS-V -- but didn't want to fork out close to $50K with T&L on a depreciating asset. Got my GTO for $25,999 -- and haven't regretted the decision one bit. And the CTS-V's interior isn't nearly as nice as the GTO's.