I've had two different 550's. The things I liked about them were the grip, very comfortable. And, I liked the sized of the knife. It was the perfect pocket size for me. I never really noticed the weight of the knife, and I'm an average sized guy at 200lbs. What I didn't like about the knife was the thickness of the blade, which really goes almost to the edge. The cutting edge on this, and most ZT's is fairly thick. It's not a good slicer. I like a knife that I EDC to be a good slicer. The 550, even when sharp, doesn't slice well. In the outdoors it might do in a pinch. But, for me, I prefer a fixed blade knife in the outdoors. One of my 550's developed lock rock after a few outings outdoors. In my mind, no folding knife can ever be for HARD use. For that the only option for me is a fixed blade. A fixed blade NEVER develops lock rock, or any kind of lock issue from being used hard. So, I got rid of all my ZT's, save one, a 561. My wife bought that for me for a retirement gift. It's serial number is 4949, and I was 49 when I retired. So, it has a spot in my safe forever.(for now) What I carry now that I like much better are Benchmades, and a few Spiderco. I really like the axis lock of Benchmade, and I've found their blade shapes and materials to slice better for me. I particularly like their cpm m4 steel. It's the best slicing steel I've used so far. I love that stuff.