I agree completely, although I imagine that comes as no surprise. I have two rules when I kayak and I try to impress them on everyone else that comes with me.
1. Always have a knife.
2. If it's not secured, it's not yours.
I invested in an inflatable life jacket because I don't like bulky ones- I even find paddling vests uncomfortable, but for not much more than a good paddling vest you can get a good Mustang inflatable. It's as unobtrusive as a pfd can get and it's still there when you need it.
Def