I've worked with those a bit at work. They aren't great but I don't think they're bad either. The bearing in the BB's aren't the smoothest, they go together a little rough, the threading on the bolts is inconsistent. Basically they are more of a pain to install and don't spin as smoothly as higher end cranks. If you can live with that they should be fine. Just make sure the pinch bolts are tight and that the dust cap isn't over tightened. You kind of have to keep an eye on them because they aren't torqued onto anything. The dust cap holds them loosely in position and the pinch bolts hold them on. If the dust cap is too tight they won't spin well and if the pinch bolts come loose they could fall of. That isn't a flaw in itself, just something to keep an eye on periodically (not difficult to do).

I think the only thing "fundamentally wrong" with them is the name! I mean c'mon "Gossamer"???!!! Who came up with that??