Re: Evolutions or stock pickups for '89 RG550
I suppose that the answer really depends on what type of music you play, and what your setup is. Also, consider this: I have had situations where I have had duplicate copies of the same guitar, put the same model of pickup in both, and yet both sounded different to some extent. Evos, from my experience, tend to lend to a more mid-rangey sound, and I'd expect even more brightness with Evos in a guitar with a maple fret board. If you play metal or music with lots of hard rhythms and/or palm muting, then fuggedaboutit, don't go with the Evos - but if you are looking to brighten up a dark-sounding guitar/amp/speaker setup and want the articulation you'd normally expect from a pickup meant for soloing as its primary function, then I'd recommend the Evos in a heartbeat.
On another note, I have owned several Ibanez guitars where the stock pickups were better sounding than the Evos. In reality, I have never owned an Ibanez that I liked the Evos in. My Evos go in my custom builds. My Ibanez guitars tend to stay stock.