Thanks for all the replies, everyone. Seems like I won't be upgrading as soon as I imagined, which is always a pity . Hopefully more people get the AX-7 so I can see how it sounds like. If not, will probably get the BA200 or R-50 for an up/sidegrade.
I tried the HF3 (similar to HF5?) but didn't like it. The dry mids and small soundstage didn't appeal to me, but I can see it being similar to the RE-ZERO.
OK, I have my IE800 and have let them burn-in for about 20hrs so feel like I can make a post about them for you. I will have to say that out of the box I wasn't as impressed as I hoped to be and I have done a significant amount of tip rolling to see if I can find I tip I like (right now I am actually using the large single flange tip that came with my JVC FXZ100 (which I hated on that IEM) and am getting the best sound out of these so far. These are a deeper insertion IEM but not an uncomfortable one. I do think the burn in has helped these improve and will continue to let them burn in for a another day/evening or two.
Currently I would say these are more of a midrange lover IEM than my desired Mid/treble oriented signature. They do have more bass than HF3 (but possibly not as visceral), they also are not as dry in the mids and they definitely have a larger sound stage. The treble is not poor though, just not as sharp and sparkly as I like. In fact I may a bit of your opposite in that I like the dryer mids of the HF3 so find the IE800 a bit lacking in that area for my tastes. In my case what I want is my SRH-940 or SRH-1440 in an IEM form and the IE800 isn't quite that IEM. But it may be a very good choice for you.