I have a 240GB SSD OCZ Agility III, installed in an iMac Mid 2010. It works very well with no problems at all. The SSD isn't the fastest ever but the SATA-Controller in the Mac is SATA II (3GB/s), so the Controller is the Limiter.
These Comments rapidly fade out after the first few Month on the Market, because it will be copied by all the Competitors and become no longer relevant. Pro-User will buy 1TB or 2GB, all Consumers buy 256GB or maybe 512GB, if Money they realize 200 Bucks are cheap for such fast Storage.