haven't tried the evolver but i love my little MFB synth 2!
here's 2 tracks using it for basses:
http://dtr.wanadoom.nl/dtr/dtr-strange_intentions-03.mp3http://dtr.wanadoom.nl/dtr/dtr-BBB-02.mp3'bout the build quality, i have no complaints whatsoever. yes it's plastic but so is the evolver, right? btw, having all the knobs in front of you is quite a pleaure! i know this matrix editing from my microkorg and adrenalinn and it can get annoying after a while. i'd go for an MEK if i'd get an evolver.