I haven't used them nearly as often as fiends, or even as much as slaadi, but I like them.
As far as popular perception goes I think they were unfortunately hamstrung by their goofy 1e artwork, but then again some folks fondly remember the flail-snail and flumph as being totally awesome despite the goofy artwork, so color me confused.
I don't care for them as constructs in 3.5 however. Outsiders with construct traits and some superficial similarities sure, but it doesn't make sense to me to have the exemplars of an outer plane as anything other than outsiders. Now it's plausible that we could say that the construct bodies are just shells through which the true outsider spirit (drawn from the energy pool in Regulus, or splinters of Primus perhaps) interacts with the world, but I'd prefer them as outsiders as opposed to trying to rationalize them as being constructs.