You'll wear them for lots of other water sports. They're perfect for dinghy sailing or working the foredeck on a sailing boat. The kayaking PFD is short waisted and has large armholes that won't hinder your mobility. They also have well positioned cinch straps to get a secure fit. Some of the better manufacturers are now making women's models, which offer an even better fit and more comfort.
Pockets are an important feature of a lifejacket.
Most boaters attach their nose plugs and a whistle to their jacket and keep their sunscreen and Chapstick in their pocket. Most pockets also include an internal loop to attach your car keys too. Best to have your keys on you and not attached to your boat. Most lifejacket manufacturers produce a woman's model. It's important to try it on though.