Well you are definitely talking about and comparing two extremes it would seem to me. Of course the folder would be much easier to carry, and much more useful in day to day activities. Of course if you live in a wilderness with the closet town 100 miles away, then the parong just may be useful.
Ok, just looked up the parong and see that it is a different knife than what I was thinking it was, had the thought of a big bushwacker. The parong is a small fb with a 3.7" blade, and a ring at the end of the handle. I'm just not sure about the ring at the end as that looks like finger breaker! Plus I couldn't find a blade steel listed. The BM w/390 is a proven design, and the steel has had great reports from all over.
I like the Fox knives and have one, a Deimos folder, that has great construction, and great fit/finish. The N690Co blade steel is a very fine cutter. I know that Fox, as well as other Maniago companies, use a lot of 440 series of steels, principally 440A/440C. Not the "super steel" that M390 is, but still a good steel when it is done correctly. I believe the Italian cutlers of Maniago do it correctly.
Btw, Is the RMD LE the Ratman deu Limited edition?