Re: Team-J Prestige RG1570 VS. '90 540sfm; painful dilemma, need expert advice!!!
For me, I like both. I have a new prestige (rg2550Z GW, rolled off the line in 2012) and an old used 550 and 560. Personally, I like both for different reasons (forget about the vintage factor).
I like the overall playability of the old school Ibanez more. The old Edge and Lo pro bridges are awesome. I rarely need to tune them. Even if I do lots of bending they just hold their tuning better. Also, I like the overly lacquered necks. they just feel smoother than the newer, lighter top coat.
However, that doesn't mean the new stuff is bad either.
I have an RG1550 and a 2550, both play amazing. I tend to favor the 2550 only because it's in Eb tuning and that's the sound I like most, but my main standard tuning axe is my 1550. The 2550s neck feels a lot smoother than the 1550's so it plays faster, and near as fast as my old 550/560s. The 5 piece maple/walnut neck is REALLY sturdy.
Another thing I like about the prestiges is how "new" they are. Basically, the 1550 had been sitting in the guitar shop for some time, probably played a few times by some people but I am the first owner. Only people who work at Hoshino actually touched my 2550 (I got it direct from their warehouse as it was stocked there).
There are positives and negatives to both, but if it was me, I'd keep the 540. Old 540s aren't as easy to come by as RGs (although I don't really know the current US market) and old 540s, if in really good condition can fetch a lot of money later down the road.