I bought an XM18 3.5" Fatty Flipper from KnifeCenter about a month ago. It looks nice enough, and it sure feels solid, but I can't say I'm impressed with the flipper action. The flipper will take it past the detent, but it takes a good flick of the wrist to open it the rest of the way. I have a Hinderer-designed ZT 0562 that looks as nice and feels as solid, but the flipper action is much better and open the knife completely, without the need for any wrist-flicking. I haven't used and abused either of them, so I don't know whether one will hold up significantly better than the other, and it's S35VN versus Elmax, but based on what I've seen so far, I'd pick the ZT for less than half the price.