I've never used tape so can't comment on the relative ease of changing a flat. I have had tires which the PO had taped. Small PITA to get the little leftover nubs of tape off.
As for the no-glue-opposite-the-valve trick. I'm aware of it but never seen to remember to it while I'm applying glue to the rim. Hasn't been an issue removing the (thankfully rare) flat so far.