Maybe it's not necessary now, i made a comparison by uploading a number of identical samples, stretched them with the different methods, such as Complex, Pads, Monophonic and so forth. Turned out to work great with some of them, and sounds shit with some. "Rhythmic Material" for example is not to recommend with rhythmic guitars as i've read on some random page.
I've managed to pinpoint the problem, still though I'm not a 100% happy with the result. Is there maybe a more sophisticated way to stretch audio in
logic?