First thing to remember about any browser you choose you use to play WGT is how well it works with flash, And which type of flash that it runs. That is if it is NPAPI or PPAPI aka pepper flash. Mozilla and Maxthon run NPAPI flash and most browsers running it work very well with flash. Most if not all up to date Chrome based browsers use PPAPI pepper flash. Although pepper flash is better than when it was first introduced it is still rather sluggish responding to mouse clicks.
If you find a browser that you like to play WGT with keep that browser set "NOT auto update. Because a newer version might not work as well as the version you are running at the time. And with Chrome based browsers an updated version might switch to pepper flash only and as I stated earlier pepper flash just isn't as good for WGT as NPAPI flash.
Best thing you can do is experiment with different browsers to play WGT and when you play use your chosen browser for playing WGT and nothing else, Use another browser for the forums and videos and the like.