We love repositioning cruises. We've done the Jewel OTS repo Boston-Florida for six years in a row, and will do it again this October. Plus, we're doing the same itinerary on Brilliance OTS in October '13. We've also done two repos from Harwich to Boston.
We love them for a variety of reasons - seeing old friends again, enjoying the ships themselves (really like the Radiance class), etc. Do we get tired of the same itinerary? Nope!