I think the POD XT Live is the best multi fx out of your list, they are amazing. I used to use the Boss GT3, which absolutley kicked ass in so many ways! Multi fx are a great studio tool. I've found the GT8 to be way too complex for my taste. I sold the Gt3 to get seperate pedals, which I now prefer, but it's took time to get all the pedals I want, seperate pedals seem better sound quality and are more unique.