To me, the problem with the copies, is the cheap pot metal blocks won't hold the string ends in place, and they are always slipping. Also the screws strip and break, and the blades wear much faster.
I agree, I stay away from the cheap copies. The Schaller and some Jacskons (590 and even the JT6) are good trem units. Probably others, but I have experience with those.
Exactly.Once the edge of the blades starts to dull you're screwed.And with the cheaper metal they wear much faster,and it will never come back to pitch if you slam it down so that the strings get sucked into the magnets of the pickup.
If I understand correctly, trems that dive only can be tuned down with no problem. The trem is built so that it never tilts backward. Therefore, when tension is released from the strings, the trem doesn't move backwards because it's built not to. I believe tuning up could be a problem.
As far as the floyd rose, the quality won't change your difficulties in alternate tuning and it has nothing to do with tuning stability. If you loosen tension in the strings, the trem will start to tilt backwards. It's really not a huge deal, the change is barely noticeable, but you may have to retune the rest of the strings.
Now, if you were to REALLY detune it, like a full step down or drop-c, you need to adjust the tension on the trem. It's not extremely difficult, but takes time and patience. I hate it (really tedious work).
Basically, a guitar with a floyd rose is made for staying in one tuning. That's why i bought the tremel-no; best of both worlds.
Rebranded floyd roses are trash and the quality does change how they work, if a rebranded floyd rose worked as good as the real one then why does the real one cost $250+ and a rebranded is $50? It's like comparing a Epiphone Les Paul to a Gibson Les Paul, they look similar and that's all, nothing else is the same.