The grapple is such a handy addition, and you guys are smart to get a tractor with good loader capacity when using one. I always recommend a dual lid grapple as opposed to a single. They clamp oddball stuff better. I have one on my Takeuchi track loader and I have moved some massive oak logs, as well as a lot of brush. They are hard to beat.
One thing to watch for if you are getting your first grapple, is that you can easily bend the loader tilt rams on any brand of tractor if you have the rams fully extended (where they are weakest) and then drive forward or back with the tips of the grapple stuck into something or against something. On most hydraulics for compact and utility tractors, when the spool valve is centered (not operating the cylinders) then the pressure in the cylinders can't reach the pressure relief valve. If you have the grapple against a big log and fully tilted down and you drive the tractor forward, several things can happen 1) the object can move 2) you can spin your tires 3) you can bog the engine or slip the clutch or 4) you can break something. So be careful.