Thanks for the input guys, I really appreciate it.

I think from what i've been reading the diamond pro probably suits me better. Purely because the caliper is a tad longer and the fact that its not as beefier as the Xtreme.

I'm afraid that the carter releases are a bit over my budget but they look impressive to say the least.

It's between the diamond pro and the t handle thumb push. Though using the thumb push would that be any different/better than the pro?

There is quite a price difference.