Down-time as combat has more to do with stun-locking mobs than with dodging anything. Add to this that GS is quite a bit of an investment into Sub that a solid Combat build really can't afford. And, well there ya go. It's good for PvP, but for soloing... not so much imo.
What you can do is spec into Reposte without giving up too many DPS talents in Combat and it's useful for soloing. I used it in my leveling spec to some success. At 63 you're probably in Zanga and Reposte should help with some of the naga there, for example.
Might consider
this build at 63.
Good luck