Hey Guys,
I just had the opportunity to wear it with my tenor and bari (low-A). ggmiller is correct, the rigid back braces prevent any upward pull at the waist. Instead I feel a slight pull backward like someone is gently pulling at the back of my belt. This is somewhat noticeable with the bari, much less so the tenor. Wearing the tenor is a snap and I really don't feel any great amount of pressure anywhere. The bari places the pressure near the top of my shoulder blades and the top of my shoulders. Although it's not exactly the same, the system sits about where backpack straps would.
For reference, I'm 6'2" and 260. The harness comes with two waist extenders for us... uh, 'plus' sized gentlemen. I've got a 40" waist and use one of the extensions. The back braces on mine are fully extended. It appears to be well-constructed out of quality materials and folds up into a neoprene bag that fits in the bell. It's really starting to grow on me and I already favor it over my Neotech harness. Time will tell, of course!