Not sure if I posted an update to this, but I ended up buying a mini seeker. I've been out with it 3 or 4 times and so far I'm loving it. Super light, and the angled front really does make a big difference. I also picked up some rigid arch insoles, like steel shanks, for my boots, which also make a pretty good improvement as well. Those 2 things combined have made things much better for my feet. My knee hurts no matter what, so I just have to live with that.
As for the JX3, I have one! I bought it a couple months ago and have practiced with it in the yard. Super comfortable! I haven't taken it hunting yet because I've been trying to nail down my mobile set up, but now that I've got that pretty much set, I can do some hunts out of the JX3. I've already got 3 pre-set climbing sticks set up in some good spots, so I've just gotta get my butt out there with it. One thing I need to work out with the JX3 is my gear/pack. I know I can rig up a pack inside the saddle, but I don't really own one that would work well for that. I have an old Cabelas fanny pack that is pretty big so I may try that, but it isn't quite big enough. I like the JX3 packs they sell but I've spent enough money on hunting stuff this year! Gonna have to find something that works though.