I climb with the Master II and love it. Light weight, durable and comfortable. Every thing is where it needs to be. My hand saw is easy to see and reach and does not get tangled with my chain saw lanyard. The left chain saw biner is great for clipping a pull line, easy to reach. The accessory loops allow for lots of storage of slings, etc.
I would never go back to one of those basic butt strap style saddles after climbing with the leg strap style. Having to pull the butt strap back down is a thing of the past along with the squeeze on your hips.