When I first bought them, I had to replace the filters after only 2 days and I was ANGRY. But then, as I experimented with different eartip sizes, I found that there are many ways to wear the Q-jays: foamies, small eartips that make a good seal DEEP in your ear, or large eartips that make a good seal that isn't so deep inside your ear canal. I was doing the small eartip fit at the time. I switched to the large ear tips, and the sounstage dramatically improved (very dramatically), and I haven't replaced my ear tips ever since. I also make a point to pour water in and out of my ear when I shower, so that might help, I guess.
Also, something to keep in mind: don't wear them within 30 minutes of showering. Or else, you can be pretty sure you'll have to replace your filters right then and there.
Anyway, so long as you use common sense, you can really minimize the filter problem, though everyone is different, and ymmv. I recommend starting with the largest ear tip, and working your way down to the largest one that will fit your ear. It may feel awkward at first, but it really does help in the long run, and it becomes very comfortable once you're used to it.
Also, there has been at least one case in which I thought I needed to replace the filter, but, just to check, I laid down the earphone for an hour, and when I put it back on, the sound was back (presumably because the filter got wet and was blocking sound, and leaving it alone allowed it to dry up again).
