We used to sell the freedom harnesses in Vegas, I really liked them. I have an easywalk-no pull one and I hate the way it impedes the shoulders, I am always worried I am damaging the shoulders so I only use it if I need a quick throw it on and no pull option. Sloan knows how to step out of it in .5 seconds, heads up.
The Julius k9s are cool but not what I would recommend as a mobility harness. They pull off rather easily and imo are stiff. For looks there are few out there that are cooler considering the name plates but functionality doesn't impress me. We sold those as well in Vegas.
For a really efficient mobility harness I would look at the ruffwear or a tactical harness. It sounds silly but with the hiking we've done and the need to literally pull our dogs up or lower them down by harnesses I haven't seen anything with better support. They aren't cheap though, unfortunately.
Here is Sloan in a tactical harness:
https://sphotos-b.xx.fbcdn.net/hphotos-ash4/293253_921482399958_91141667_n.jpg (Giant photo)
We also sometimes leave doggy seatbelts on Shamoo for help when she's on a slippy floor or going for a walk where she may tire easily but they don't really support the rear which is where she's weak.