F&R is usually not a problem with longer lenses at not extremely close distances. It is a problem with 24/35 in most real world cases, and sometimes with 50mm.
One technique that works quite well is to use the rear AF button in AI Servo mode, and the outer AF points. This increases their precision tremendously, at least on my 5D2. The precision is similar to the center AF this way, with apertures like f/1.2-f/1.4.