I've bought 6 bodies (2 FM2n, 1 FM, 1 FG, 330, and 330F) and a number of lenses from them over the years with only 2 problems - the FM and a 65mm lens for the 330's crapped out after 3 or so years. Since they don't test I usually stick with EX on the totally unsupported myth that if the cosmetics are in better condition, they might not have been used so hard and the mechanics might be better.