It's interesting. Been going for six months now... One thing that's good is around keeping your upper body in line... You don't seem to ever counter balance. It means you can move into the next move more easily.... Watching the Brazilian kids doing freestyle is similar, they don't topple and most of it is done from a vertical upper body
Tried to find a photo to illustrate

OK, he's showing off but he's completely solid
Re tai chi itself. It's a bit slow learning and you 're in a group that goes with the slowest person. Also, it doesn't work your flexibility as much as yoga. If you're going to try to pick up then you'll be disappointed as the average age is north of fifty.
On the plus side, if I ever get attacked by zombies or very slow people, I'll be able to defeat them all with style and grace.
Are there any martial artists out there who think it helps windsurfing?