Thieves offer more opportunity, wider path as it were. A thief can be in any cabal (maybe not entropy not sure), any align, any ethos, most races. A thief can become a guild leader. Raiders can be fun, but if you are the type who needs to be in a cabal, well, pretty sure that is denied there. Raiders are new'ish but you should be able to look up successful ones to see what does/has worked from their skill set, if that sounds fun to you go for it.