It's hard to give advice about someone else's bike addiction. However, I just wanted to point out that I keep thinking of the pic you posted of you and your Ruby when you first got it.....what a smile! Even though I've read all the great tales of mountain biking here, I'm still a roadie. If you already have a shoulder injury, I would think trying to port a mountain bike around would be a recipe for reinjury. About a cyclocross bike, sorry I want to add one to my 'fleet', too.

Probably not any help, but good luck in your decision. You'll do what's best for you at this time.

P2