I'm also not a fan of rubber mulch, although it may work differently where you are. Down here, it gets hot, (and smells!) so it doesn't regulate soil temperature well at all, then also (unless it's on top of landscape fabric) it will sink into the soil and haunt you forever.
A good organic mulch (wood chip, bark, pine straw, even leaves) is a good insulator, prevents erosion, regulates moisture well and breaks down to enrich the soil. True you do have to keep adding to it every few years, but in the long run you are improving the soil.
