I adore them, and they're worth seeing, but I don't know how "good" they are--in fact, watching them, we marveled at how crap it all sounded live: such ridiculous, tacky "industrial" drum sounds, and lame versions of old songs. Alan Vega looked for all the world like a homeless person ranting over the beats, covered in patches and dangling rags, and a ludicrous head-wrap, Rev looking like Don Knotts in a bondage outfit.
But if you think about it, it's music that has always confronted standards of taste and good quality, part of what has made them so unbearable to so many for so long, caused riots, etc.
--needless to say I ended up appreciating it quite a lot, not least for the perspective it gave me on what the band has achieved