I'm fond of the Accu-Tac design for stability, but that panning mechanism on the FC-4 wouldn't be my first choice - it's extra complexity and height above the boreline. I use a WB-5 ARCA for local PRS style matches and also have an older FD-4 ARCA that gets loaned out to new shooters. The WB-5 is very stable due to the wide stance, but there IS one prop here locally (the curved side of a drainage culvert) where it is too wide, and I have to make do on that stage. The "-5" height is perfect for me, never been too tall with the legs at 45 degrees, never been too short with the legs at 90 degrees and extended, always been able to get level between differing leg extension and the cant feature. For long range shooting and matches, the weight is a good thing.