Watchful,
Thank you so much for your input. and you're right, I'm finding that my range of moves is severly retarded using this grip, and like you said, pretty much limited to one or two.
The reason I like it is cause those one or two moves are AMAZINGLY effective! It's crazy! I have yet to spar against a length of chain, but I have sparred against a knife, a sword, and a Jo-staff,(my former weapon of choice before God himself showed me the hawk!

)
With the staff, i find it is pretty much a toss-up in the effectiveness of MY grip(which I'll call the reverse-handle grip for now( and the effectivness of the conventional grip. so I go in using the conventional grip and then switch to the reverse-handle after a two-handed block by grasping the reverse-handle grip with my left hand.( my being ambidextrious helps on that one.)
Against the knife, this is wickedly effective. I found that, in sparing person quick with the knife, they just waited for me to swing, dodge, and quickly countered. (knife fighters are scary quick aren't they?) but if I use the reverse-handle grip, I can move just as quckley and unsuspectingly. and also had the advantage of being able to attack his knife hand just as quickley, from further away.
With the sword, I think it is just up to everyone on what they prefer. With the conventional grip you can hook and trap, looking for a moment to strike. and with my reverse-handle grip, you can practically fence with them, bring them in close to you to strike. the advantege of this is that, short of slashing, you take away the swords advantages of stabbing and length by bringing them in so close, which I prefer.
This grip also allows you to put your free hand on the proper end of the handle and perform a wicked two handed slash.
And lastly, you can use this grip to win a fight in a non-lethal manner, if the situation required it. this grip allows you to perform some DEVASTATING blows with the handle (cause of the weight in back) that are extremely accurate.
I did'nt mean for this post to be so long, but I hope it will help improve your sparring sessions, which, from the way you talk, are already pretty advanced.
I appreciate your input very much, And I wish you the happiest holiday.
Tommyhawk. (Ian)
P.S. what do you use to spar with chain? actuall chain? or plastic?