Jeff,
The Threat acts very much like a reactive. The core is identical to the Triple Threat only the TT has a stronger coverstock.
The Thrash has a different core completely----and gives a different reaction. The Threat is very long compared do the TT and the Thrash. The TT has a stronger breakpoint than the Thrash. The Thrash is smoother, gets decent length and in my opinion is the better ball of the three. It has very good impact at the pins and is extremely readable for a pearl ball.
SO, summarize my ramblings, here is what is seen when all 3 are on the same condition:
Theat----long, reactive type breakpoint, no good for carrydown
Thrash---versatile, smooth breakpoint, better ball to square up with
TT-------very strong breakpoint, and a little sooner than the Threat.
In all reality, you can make a complete arsenal out of these 3 balls. Sand the TT down to 400-600 grit and it can be an oiler for most bowlers. Drill the Threat to go really long and it will work on light/med, basically everything except the very lightest conditions.
