I've been using 50/50 peat/filtered pool sand for most of my carnivorous plants, which is a mix that seems recommended in most of my readings. I've only been using it for a couple of months, so I can't comment on the long term potential for soil compaction, but many those recommending that combo were long time growers.
Others (to a lesser degree) recommended peat/perlite combos, the only real complaint I remember about perlite being it's tendancy to "float" to the soil surface. That may be less of an issue for carnivorous plants if they are bottom watered rather than top watered like "regular" potted plants.
The main concerns most seemed to have with what type of sand to use seemed to revolve less about granular size and more around mineral/salt content. Filtered pool sand was recommended due to the fact that it's washed/rinsed so as to have less/no effect on pool pH levels. As for grain size, larger was preferred, tho, all but the finest were considered ok.
