My preference is a neurosurgeon over an orthopedic surgeon. My wife, RN, insists, also.
L4-L5 fusion for spondylolythesis(sp?), spondylosis (sp?) and bulging disc October this last year using minimally invasive surgery. The neuro had the training, credentials, and, more importantly, the outcomes and recommendations from OR nurses (they are the ones who really know what goes on) that were important to me. I saw three neuros before deciding. Most "referrals" don't mean much - they may be neighbors or their kids play on the same soccer team or whatever. Generally, the referring physician hasn't a real clue about the surgeon's outcomes - a critical criterion, IMHO.
http://www.spineclinic.com/prusmack.html
some more good info here.
http://www.spineclinic.com/patient_edu.html
Back at swimming in 14 days. On the mtn bike in 18 days (more vertical than the roadie). Fully recovered, no apparent loss in flexibility - actually, since I am doing more stretching, the flexibility has increased.