Re: questions about the JEM 777 Edge Backstop experience
When I first bought my 94 Jem I only had to tune it when I change strings, no matter how crazy I was on the trem arm (and I snapped the arm once with it, to give you an idea). These days the stability isn't that good, up/down has a very slight bias where it will go sharp/flat, but that sharp/flat is always consistent. So if I do a divebomb and then tune and lock + fine tune it will 100% be in tune after pushing the trem down even if it goes very slightly sharp on pull up... Which means in terms of tuning it I very rarely have to touch anything, the knife edges are just worn to the point where there is a slight bias in the return point based on up/down trem usage, so if you tune it after pushing it down it will always return to tune after a pushdown.
If you're having to tune your guitar often then there is something wrong. I had it on one guitar once driving me nuts and I had just not tightened the string nuts enough causing minor movement, sometimes old strings are the problem, sometimes the seating of the bridge or the posts can be off. But under normal circumstances a good condition bridge should almost never need to be tuned regardless of how hard you go with it, and that's even the case with the cheaper "Floyd Rose II" on my Strat, which has had years of abuse too (99 model).
I'm still waiting on my 777 to arrive and haven't tried the backstop, but my 7V has a Tremol'no inside it and it causes no issues.