Not sure what the 'GT' refers to but I have a Crosman 357 with 6" barrel and a S&W 6".
S&W is far superior build quality and a real joy to hold and fire. Accuracy is excellent. Trigger is good and the pistol works with a satisfying mechanical feel. Expect about 60 shots per gas capsule.
Crosman is a fine pistol... I use the 10 shot mag most, but is not as pleasant as the S&W... trigger is rough in comparison and there is much of a plastic feel around. Accuracy, is, however, very good. Expect more shots per gas capsule ... about 70 or 80 are possible.
Muzzle velocity of both is about the same ... around 360fps in a garage this weather, dropping off as capsule gives up.
So you pays your money and takes your choice. I get great fun from both. Note that JSR have the Crosman as remanufactured stock at £29.95 I believe.
Cheers, Phil