If I were you, I would not send it back. If you can't hear the problem, then I think that there is no problem.
If it is environment dependent, which we don't know for sure but strongly suspect, then it may indeed develop later if you change speakers, wires, rooms, houses, etc. But your warranty is still for five years and if it hisses in three you're covered. If it's still never hissed after five years, I can't imagine having a problem after that. It will probably be obsolete anyway.
Remember, also, that the replacement unit you'll get will be a refurb. I know that the one in my rack is technically used, too, but I'd much prefer to have a unit that's "used by me" as opposed to "used by someone else." They will refurb your own unit for you if you prefer, but that involves sending yours back first, and being without while they work on it (and while it makes its way across the U.S. twice). I'm not willing to do that, after being without it for so long.
There's also nothing to say that the improvement will make it better, and not worse. That's another chance I'm not willing to take.
Lastly, I don't think the original problem is as serious as most people made it out to be. I certainly don't think it was serious enough to warrant a halt in production. I thought, and still think, that the Outlaws really jumped the gun on that one and lost a lot of sales over it. They're perfectionists; I'm sure that one of the reasons the original was so late was that they were twiddling with it.
The only upside I see to sending mine back at this point is a three or four month extension of my warranty. But, it's just not worth it. I doubt I'll be using it five years from now anyway, except perhaps as a rec room unit.
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Matthew J. Hill
matt@idsi.net
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Matthew J. Hill
matt@idsi.net