I know that being a Cisco Employee, and one responsible for the stability and support for this product, my opinion is a little biased and may not be representative of the field.... but:
I feel that 7.0.116.0/ 220.0/ 230.0 are very stable codes.
6.0 got a bad reputation early on, and alot of people made the jump to 7.0 sooner than they had probably ever intended, but generally speaking anything after 7.0.98.0 I think you'll find has been adopted well.
7.0 is intended to be the final train for the wism1 platform, so if this is a long term deployment you'll likely end up on 7.0 eventually.... might as well start now....
