They're pretty different animals. I don't own an ETAK (love the design, though), but I own an 0308 and a couple comparably sized Emersons, the Tiger and the Super Commander. (I wasn't confident I'd like the ergos of the ETAK, whereas I knew exactly how the SC and Tiger would feel.)
If you need the wave, that's an easy filter to apply. Frame lock vs. liner lock, too. The pivot hole on the 0308 is also pretty polarizing, as is the steel lockbar insert on a frame lock (0308) vs. Ti liner lock (ETAK).
The 0308 is fancier, with awesome milling on both sides; the Ti side is especially nice. It also has CPM-20CV vs. the ETAK's 154CM, and a conventional V-ground edge bevel vs. the ETAK's chisel edge. Overall fit and finish is more refined on my 0308, and it didn't need a break-in period.
Because of the bearings and especially the decorative hole making it easier for crud to reach them, I'd give the edge to the ETAK for "dirty use." I haven't taken apart my 0308 yet, but from experience I can say that Emersons are trivial to disassemble for maintenance.
I've used both companies' warranties, and both have been excellent.
Value for your money, it's hard to argue with the 0308. You're getting better materials and more polish for not much more money than the ETAK. But I'm a fan of both the 0308 and my larger Emersons.
Hopefully someone who owns both specific models will chime in, but in the meantime I hope this post was helpful.