Personally I found scene bite crap even though I know others rave about it. I much prefer Sally Hansen insta dry as a top coat.
Best tip I have found for stopping them peeling off is to make sure you 'clean' your nails be for painting by rubbing with nail polish remover until they squeak! Removes the oil from the nail surface and makes loads of difference to how long they last.
Also find it depends what make varnish you use. I have had all sorts from Barry m to Chanel but imo best of are Rimmel, M&S and essie.