I use a Tamrac N-5055 made of thick neoprene. It's a lot more confortable than the Sony's but the quick-release buckles are plastic and make an annoying noise when making contact with the camera body. I'm looking for a better solution but didn't find any so far, so I'm sticking with the Tamrac for now.
BTW I saw a couple of nice looking (and inexpensive) chinese straps on dinodirect.com or focalprice.com (can't remeber exactly on which one) which are made of neoprene but doesn't have any kind of quick release bluckles... I may order one to give it a try.