I have all three drilled 4 x 4.  Med. rev, med. speed, high track release.  Used all three on my house shot, and the TX at the PSBA tourney on Saturday.  The GT-1 is about 5-6 boards stronger than the TX, with the length of the SX.   Haven't found a good condition for the SX yet, but I use the TX on dry to med-dry with OOB surface.  OOB, the GT-1 needs more oil.  So far, the TX doesn't seem to burn up on drier shots, and it doesn't over react. The GT-1 is more angular, and a little jumpier. I haven't used the GT-1 in league yet, just practice, but I think it will be better on a fresh, medium length THS than the others, and definitely more angular and stronger.
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Formerly Patentman

The ball rolls true.  No over/under.  It revs up very fast and has a nice hard arc to the pocket.  Good ball.

From what I've seen the GT1 works great on oilier house shots,allows  people to  move into the oil,instead
of trying to find a ball that they have to throw straighter on THS.The ball gets through the heads and has a great mid-lane bite and a skid arc set up. People in summer PBA Exp are using it with good success.
 Looks like it works best on med to medium oil.