I played Brick.See the problem with using Crawmerax as an example is that it largely depended on whether or not you were a Siren. The first time I ever tried to solo Crawmerax was on my Siren and after a couple runs to finally get the hang of it, I felt that soloing Crawmerax was easy as hell. Have since tried it as both Roland and Mord, and while I managed a few kills with each, it was such a tremendous pain in the ass even using the exploit spot that I just said fuck it and stopped working at it. Actually had 3 pearlescents on my Siren from solo Craw runs.
It was absolutely stupid difficult. I gave up.