Does anybody know what the major difference between the Boss GT-6 and the Boss ME-50 is? Also, I am wondering, are multi-effect units worth considering, or is a person better off just buying individual pedals, like the Boss DS-2 or the Electroharmonix PolyChorus. Also, what is the major difference between digital chorus, and analog chorus?

If you know the answer to any of my questions, or you just have something useful about effects to say, please do, I know nothing and would like to learn about effects and which units are good.