RE: More important feature...
axle to axle length can be a little misleading as far as "foregiveness" goes. If you look at the 2 bows you spoke of, you can see they are built a little more differnetly........the Katera XL is a long risered, parallel limb design, whereas the 737 is a more traditional shorter riser, longer, non-parallellimb bow. Now being that they are 35" and 37", that isn't the point I'm trying to make. From an accuracy standpoint, if you look at what pro shooters use for indoor shoots and 3d, you don't see to many parallel limb bows on the line.They just don't hold on target as steady as a standard configuration bow.......at least that's the case for me personally. But a few pro's I've chatted with have relayed the same info to me. I shoot my 33" Vectrix very well for a hunting bow, but in all honestly, I'd take back my 2004 Xtec over it in a heartbeat. It wasen't as smooth, but it shot circles around my Vectrix, it just "held" steadier with the longer, non-parallel limbs. It's a matter in what you're looking for. Both of those bows will perform very well for you, and from a hunting standpoint, most guys will take the Katera. But if I was looking for a crossbreed hunting/3d pounder, the 737 would be my choice.
As for brace height, there's only a 1/4" difference between those 2 bows, so don't worry about it. Buy the one you like the most, with your exact intentions of use in mind. LOL......I'd buy both if I had the dough!