Does the k-x have a quiet shutter then? I seem to remember some stuff about the k-7 having a silent shutter (which sounds a great thing), but I have also read a few less than complementary things about it. I do like the (relatively) small form factor of the DS, which I believe the k-x follows.
I may well follow the "if it ain't broke" for the time being, and maybe wait for the next models. Having said that, a quick look on eBay shows that a DS will only fetch around £180, so for those regretting selling theirs....