Of the ones mentioned My vote is the PM3. I have an original Para in D2 and the lock up is just as good as the day I bought it over 10 years ago. The compression lock is insanely durable and secure. The design is as low maintenance as a liner lock only more secure. I love my Benchmades but there are way to many springs that could break or foul rendering the lock useless. I'm guessing over there it would be near impossible to fix a broken omega spring.
However, I would also suggest looking at an Emerson for ease of maintenance. My Mini CQC 15 is without a doubt the easiest to maintain and uses really common tools to disassemble.
However, I would also suggest looking at an Emerson for ease of maintenance. My Mini CQC 15 is without a doubt the easiest to maintain and uses really common tools to disassemble.