I haven't spent any time in Phuket, though will probably get down there as some point.

I have heard of the "taxi mafia" problems and found it interesting that there was some recent action taken:
http://www.bangkokpost.com/most-rece...taxi-crackdown

This being Thailand, no idea if this is a momentary blip (probable) or a wholesale change (maybe?). With the current military leadership, there does seem to be an attempt to address some tourist-facing issues...