Man... I really appreciate all the responses and opinions.
Here's what I think I have learned (don't hesitate to disagree or even contradict if appropriate):
1) You TBN folks are very passionate about your toys! (er, I mean... "tools").
2) As one poster said, opinions are indeed like butts - everyone has one - and I appreciate all of yours! (your OPINIONS, that is... NOT your, well... never mind....). :-O
3) I will love the SSQA system. (I plan to add an adapter plate to my bucket, and am already eyeing other tools I will probably want to acquire as time goes by (and money permits).
4) A grapple will be a great addition to my stable of implements, I will likely be quite content with whatever I wind up choosing, and will probably wish I'd gotten one years ago.
5) For a tractor the size of my L4310 (or any size perhaps), a lighter grapple is better (assuming it's built strong ENOUGH, of course) to minimize the amount of lift capacity you give up by having the grapple. (In my case this will be pretty important as I expect before it's all over I will add an SSQA adapter to my smaller L2850 & want to use the grapple on it some as well.)
6) For my use, I may be happier with a slightly narrower grapple than a wider one, but will prob want it to be as wide as the front tire width.
7) For my use, I think I am leaning towards a single lid - slightly lighter (and ever so slightly cheaper), but primarily I think I like the idea of having a gripping point right in the center of the grapple. I can see myself wanting to grab long trees/logs by one end and dragging them backwards, I think I want to have this load gripped right in the center of the grapple rather than offset to one side. For me, I think the center-grip feature is more desirable than the dual-gripping-point ability.
8) So finally...
THE WINNER IS - I think I will probably wind up going with the EA Wicked Grapple, Single Lid, 54".
The decision is not 100% final yet (so feel free to keep this thread alive - I really enjoy reading/learning!), but that's probably where I think I'll wind up.
I also would like advice on the 3rd function hydraulic valve kit, and the pin-on SSQA attachment to go on the tractor - are there certain manufacturers/brands of either that are notably better than others, or are they pretty generic?
Any thoughts on that here are appreciated, or... should I post those questions in another thread (or two others)?
Again, THANK YOU to all who have weighed in - I really appreciate your thoughts!
(This TBN place is GREAT!!)