The blue ones and green ones were made in the 90s(mid to late I think). This is just an observation but most of the blue ones I've seen tend to be larger sizes and the green ones are smaller sizes. I think the polished ones were made a little later, maybe late 90s, and there don't seem to be many of them around. The newer ones have only been around for a couple years, and yeah, I think it would benefit from a simpler paintjob/not so many stickers. Have only heard about the black "messenger" frame...
I have a blue one and love it. However there's no way I'd spend four bills on a beat up used one, aluminum just doesn't last that long.