I picked up a 530 years ago, which I love, but switched to the 531 on a first look in an Arizona knife shop. I carried the 531 on backpacking trips including the John Muir trail, and a week in the backcountry of Denali National Park. The Bugout just caught my eye and one just arrived today. It is lighter than the 531, has a nice belly for cutting, feels good in the hand, the blade shape and handle color make it less intimidating than the black spearpoint, the fingerguard is comfortable, the thumbstud is more comfortable, deep drop clip is an improvement, and it would be easier to find in leaf litter. No issues I can see, blade is centered, no play, handle is plenty stiff without a full liner, washers are good, etc. So far I love it.
This is just a first impression, I'll begin using it seriously in the field beginning May. I own another 6 or so Benchmades, including a mini-Grip and the amazing 940, and four or five Spydercos, including a Stretch and a Delica. Action is stiffer than the 940, but I can't complain, no different than the 530 or 531, a drop of oil helps. The 530 and 531 are closest to the 535, and I tend to carry a light blade.