Bathtub resurfacing: Do the Do-It-Yourself Kits work? (Details.)

Professional resurfacing is really expensive here. My bathtub needs a face-lift desperately. I would like to use a DIY kit.
The only kit I can find here is Mr Tubby. yes, I know

If you have used a DIY (do-it-yourself) kit for resurfacing your bathtub…and can make recommendations (for a kit, for the right way to do it, hints, tips…anything…I would really appreciate it.)

Thank you!