^What they both said. I've been through two pairs of Wave Inspire 8's and then three pairs of Inspire 9's and I'm currently on my first pair of 10's and they are the best yet. I have no personal experience of them but I understand the 6's were pretty good too but the 7's weren't so well regarded.
The basic fit an comfort is pretty much the same though and that's no bad thing. If it isn't broke don't try and fix it.