I've heard more than once , out of Festool Reps mouths no less, that Senco and Grip Tite are compatible with running the DWC-18. I'm buying some later today or this weekend to compare to the Festool screws I already have. So far, Festool favors boxes of 1000 and others seem to offer boxes of 800, but at a much lower price than that 200 fastener count gap alone accounts for.