The more streamer tying I do, and the more warm-water flies I come up with - I find myself using limited amounts of natural or water-absorbing fibers. Natural hair & fur is good for some things - and a lot of my flies mix natural fibers with synthetics - some of these pictured above for example use bucktail fibers for the tails - bucktail doesn't soak up water. I mix synthetic dubbing with natural feathers too, for example. And on some of my newest bass streamers - I did articulated combination streamers that use buck tail, schlappen, and synthetic dubbing all in one.
Very swimmy flies that don't absorb much if any water. Except for some flies that I want to fish a certain way - I and gravitating away from weighted flies, prefering to fish unweighted flies on sinking lines, or lightly weighted flies on sinking lines, rather than trying to huck half an ounce of lead with a fly rod.
I like flies that either suspend, or even will move to float upwards at rest.
Here's an articulated Boobie (I didn't name it, the Brits did) - "Double D" edition for the size of the big foam eyes - it's tied with 3 Fish Spine articulating shanks, and a size 4 B10S stinger hook.
This fly wiggles and jiggles and darts and dives when stripped, fished on a sinking or sink-tip line. Then at rest, it wiggles and jiggles it's way upward. I figure it would imitate a water snake, a gecko or salamander, or huge leech. Probably could cast this one on a 5 or 6, but I use an 8 weight because of the nasty stuff I'm fishing them around. I want to hook the fish and horse it away from the brush ASAP. This fly is 100% synthetic - simi seal dubbing and neoprene foam eyes, and it uses 10, 15, and 20mm Fish Spine shanks.