i've been using the Jantex tape, and have had reason, nothing to do with the tape, to have had the tire off and on three times now. getting it off is just about as difficult, initially, as i would want it to be to give me the confidence that it was securely attached. and cleaning the rim was a snap with kerosene (aka diesel fuel). the tape pretty much peeled off the tire's (vittoria corsa) cotton stitch backing without difficulty.
leaving a gap does help in removal, but the gap length is critical. too long and a thump when riding on smooth roads at high speeds is possible.