Laser class rules are silent on life jackets (PFDs). But if you attend regattas, the sailing instructions MAY insist on a (US) Coast Guard approved PFD. These tend to be a bit bulkier than the typical buoyancy aid.
I like my Gill buoyancy aid (relatively inexpensive), but I still have to remember to DUCK LOW when tacking, especially when the vang is on tight. And if you are tall, this becomes even more important, or you will swim
I just use the ZHIK life jacket which is now coast guard approved. I can have the vang all the way on and still get under the boom. Yes, my life jacket touches the boom but it just slides right over. You just have to get really low into the cockpit of the boat. NOB's are good but I would personally wait for the new ZHIK life jacket to come out. You can see it on the website.
I also use the Zhik Racing Buoyancy Aid. It is very comfortable, provides enough buoyancy so that my hat doesn't usually get wet in a capsize, and makes it pretty easy to clear the boom during tacking. The one-buckle adjustment means that you really need to be careful to buy the correct size and need to a have a relatively "standard" upper body shape. -- Ed