I'm rocking some Koss Sparkplugs... lol
I've eyed some of the Shures before, but I just can't bring myself to spend that much money on a pair of IEMs considering the abuse they tend to go through, I'd probably tear them up in a few years. I had my first pair of Sparkplugs for a few years and ended up having one of the channels go out (break or short in the cabling I guess). Just tossed them and picked up a new pair for $10, if I'm able to get another 2-3 years out of them I'll be pretty happy.
And obviously I'm not a huge audiophile, as far as SQ goes I'm sure the Denons are far superior. The bass on the Sparkplugs is way too powerful and muddy out of the box for my tastes, but if you cover the ports it really tightens it up. And I use those Shure triple flange silicon tips with them instead of the foam ones they come with. After these changes I'm happy enough with their sound and comfort.