You know, it's impossible for me to compare the previous model to the GT because all I've hit with is the GT and GT Plus; TWE sent only the GT versions to me by mistake. Additionally, the demo is strung with a string I genuinely dislike, abhor really, probably more than any other, so bear that in mind. That said, for me stock balance is very nice, though could be more headlight. Swings awfully fast, which is nice, and placement is very good; overall I find the frame a bit too light, and lacking in oomph. I usually hit with a prestige mid or PSC 6.1, both stock. During rallies and serves with the GT, there is a distinct metallic ping sound on balls struck higher in the sweetspot and this IMO is the tungsten (note: I don't play with a dampener). Overall, the frame is solid with a plush stringbed, but definitely needs a lead diet to be playable, for me. I'd suspect that if you love the original frame you'll have very warm feelings about the GT.
btw, in your pic of the grip wrapped by P1, I'd agree there is a bulge under there just above where you'd grip the handle, which I'm sure is lead tape that was wrapped to balance the frame out to your spec. Really nice looking job by P1.