I bought a pair of Time Atac Aliums in 2001.

I've commuted on them 365 pretty much ever since so that's a lot of in and out due to traffic, although I taught myself to trackstand in them last year so now I stay clipped in more of my commute. I've never had any problems with road filth or salt in the winter and every morning when I jump on the bike they make that nice snick, snick clipping in.
They're still working perfectly just like when they were new and the last time I gave them any maintenance was, uh ... hmmm I've dont think I've ever cleaned them . They maybe got powerwashed once when my commuter and mountain bike were one and the same. The general consensus is that the Time Atac Alium is to all extents indestructible. I've seen one picture of some dead ones here but the guy looks like he beat the sweet jebus out of them.