i personally use a POD XT LIVE and am very happy with it.very convenient with usb recording and all. the gt8 requires u to buy a midi converter if u intend to record without an audio interface....
if you're going for value. i'd say the Korg AX3000G is really good man. for a price of only 300+. the distortion effects are really good man. and the wah is really really power. was really surprise with it man.
just go try out whatever multi effects u can. then decide. alot of things to consider beside sound, especially the gt-8. gotta take some time to learn how to use it.