I haven't been tattooed extensively, but some of my friends who have been said the feeling of the needle going over bony parts is REALLY unpleasant. I'd probably take scalpelling because it's over and done with faster, but of course this comes from someone who laid under a scalpel for 12 hours to get her whole back cut. :D
Don't lie about your stretching history kids, the catbutt always catches up with you eventually. ;)