Everyone is different but overall I prefer the kayfun3.1, never had any problems with it.
I can't quite get the taifun gt wicked correctly so that's my biggest negative! I get occasional leaks from the airflow with a slight gurgle but the liquid darkens too and ends up tasting rank :-(
I prefer the draw on the taifun and the flavour really can be great but I always leave it home and grab the kayfun!
Kayfun also looks great on the stingray x, nemesis or 4nine etc but my taifun stays on my infinite caravela (23mm), at least until I get a paps x!