I have had my WFR in the past, but haven't had a refresher course in a few years. I think it was useful. I think even your basic CPR/1st Aid refreshers are useful, as staying familiar with basic steps is important, as easy to forget if you don't think about it for a while - use it or lose it - type stuff.
It can be easy to forget even the most basic of training when faced with any sort of medical situation on the river/wilderness.
I definitely used various WFR training skills, at the Gore Race in 2010, when one of the men paddling the shredder was found by Bob C, ("Rockin' Rio on here) face down in the eddy below pirite. Bob singlehandedly paddled the guy to shore and had started the assessment process by the time the rest of our crew paddled over (via raft).
I don't know what training Bob has had, even though I paddle with him often...I should know this..as its good to know these things of your boating buddies....but he definitely initiated the assessment of the man. (Still super psyched to have Bob as one of my paddling buddies!!! He saved that guy's life.)
Everyone involved worked together so well that day to build the litter and safely get him up the scree/talus to the rail road tracks. There was a lot of excellent team work done that day and I think it was, at least, in part to the various levels of training that were on board.
I think at the very least, it introduces potential scenarios to get you thinking about what you might need to do if the shit hits the fan - also might give some confidence that can help to keep you more calm under pressure.
I know my crew and I are planning to take a swift water class together this spring to add to the cohesiveness and communication styles we already have with each other. It will also help us recognize each others strengths and areas that can be improved upon.
Nice topic- I almost forgot this forum could contain such useful information