Steve, I follow CFFB programing and just started using straps. I love them. The constant heavy lifting in CFFB left my forearms feeling so fragged that I couldn't grab anything. I have just started using straps on my heaviest working sets for lifts. My grip still gets worked on all of the warm ups or at the start up ramping up to a max effort. But, when it gets really heavy I use the straps and am just limited by my back/leg strength. This gives my grip more of a chance to recover. At the very least it means I can do lifts I could not otherwise do because my grip needed to recover, but I suspect the the more reasonable training volume/recovery will actually let me grip strength improve faster. Only time will tell on that one.
For John Welbourn's (creator and programer of CFFB) take on straps see http://talktomejohnnie.com/lifting-weights/straps