Re: My RG550LTD sounds better than all my Prestiges
You have probably gotten yourself a really good copy of that 550.
So you have already answered your question with "maybe the wood on this particular guitar just resonates more".
It really has noting to do with type of wood or type of pickups or anything like that.
It is all down to the luck of getting a good resonant neck with a good resonant body and that the body and the neck like each other.
You can find those guitars made of any type of wood and in almost any model of guitar (sometimes even in really low level models).
The plays better is just a a setup thing, I think.
And also that we tend to feel that good sounding guitars plays better because it sounds so good.
Anyway, don't try to analyse it, you will never get any thing you can use out of it.
Meaning, you can get the exact same guitar and it can be really boring.
Just smile and be happy about that you found one of the good ones.
As a quick example.
I was looking for a "as close as possible sound wise" backup for a really really good RG3120 i have. I went to Ibanez stockroom and tried a massive amount of guitars.
I started with guitars of the same model, the guitars of the same wood and so on, but didn't find anything really close. Then I tried, just for the fun of it, a JEM7D and that was the closest guitar to the 3120 I could find. I could not hear any difference when I closed my eyes (they feel different, so I could tell that way).
I mean, they have different pickups, different wood, different almost everything and still sounds almost exactly the same. But when trying at least 30 of the exact same 3120 model could I not find a single one that sounded the same as my 3120.
Are your 550 light or heavy (wight)?