Can't speak for Extreme White RV Roof tape, but I've used Eternabond on all my RVs and been very happy. Good preparation and planning is key, as you mentioned making sure all surfaces are clean and having the right tools (one of those rollers for laying down lineoleum is very useful for getting enough pressure). Start slowly and make sure you correct your line as you go, once the tape is down it is down, and I've had plenty of creases. It doesn't need to look pretty (but nice if it does), as long as it covers all the seams. Don't forget to do any slides too.