I do think a Trilobite is a nice tool, I just expect it to rust and that would bug me. Maybe I'm being anal about it.
I don't expect the titanium edge to see much use, so I haven't been too worried about titanium not holding an edge. Carbidizing seems to be the solution for giving titanium a good edge, though it doesn't seem to be offered on any dive knives I've seen. I haven't found a service, but it should be possible to do to any titanium knife.
The DGX knife is a much better price than the Halcyon. I've read the Halcyon Explorer is indeed the same knife, but with a better nylon sheath.
EB Custom Knives looks like this:
I'm guessing they are expensive.

It's hard to spend more than ~$120 (which should buy a very nice knife) considering how easily they are lost.
I came across the
NRS Titanium Copilot. It has a squeeze release using plastic clips. It's 3/4" (1.9cm) shorter than the Wenoka due to a 3/4" shorter blade. No line cutter and it's made for a lash tab, not sure how well it'd attach to webbing. I think I prefer the Wenoka.
No BCD, I have an xDeep Ghost so it'll have to go on the webbing (or inflator hose, but I'm thinking it's bit big for that):
Do you think the Wenoka will slide on the webbing?
H1 steel is interesting. It holds a better edge than titanium and isn't as rust resistant, but better than stainless.