loose,
my EMB XF goes 'long and flip', and we don't get Roto-Grip balls in England. Both Thrash and Threat have been discontinued, and a quick look at the local pro-shops websites, I expect them to be very hard to find in this country.
J_Mac,
Sorry. Off topic:
I've noticed that you have a Prime Time; I'm getting one soon.
Most of my bowling balls go long and flip, I think with the correct drilling, the Prime Time should give me this reaction as well (may even be similar to EMB XF).
What is Prime Time like? I've read very good reviews (for a 'cheap' ball) on this sites.
Also have a Power Groove Reactive (pin above and between fingers, CG and pin both on perpendicular axis line), much stronger ball than expected.