L4-L5 fusion in 2008 here. Best thing ever. I had lifelong wear and injuries from athletics, as well as dessicated discs in the lumbar. Bottom line for me is renewed flexibility and strength. My rules of thumb were: 10 days- well enough to resume work; 10 weeks - well enough to resume full activities; 10 months - fully recovered (in time to remove the hardware, surgically). That only required about 6 weeks for full recovery.

I joke that the only titanium frame I've ever owned was inside my back for a time...