Hello Galger!
There are lots of treatments available for Spondy - before you think about surgery have you though about or tried things like physical therapy? Injections? Life style changes? Often Spondy pain can be controlled by any one, or corabination of these treatments.
If however you decide to go the surgery route, your recovery will depend on age, level of fitness, and other medical factors. I'd recommend discussing your recovery process with your doctor - s/he knows you best, after all! I recently had the very fusion surgery you would be getting - at L4, L5 and S1, and I can tell you that only 3 weeks post-op I already feel better than before the surgery.
Good luck with your decision,
Wishing you the best of health,
Becky