Having one of each, right here in the room with me, most of what has been said above it right on. The thing I have noticed about my two is the edge behind the primary bevel (?) on the SWATmandu seems thinner than that on the INFImandu. But this is just two examples. I have another two samples back home (I'm on det right now), and I can say the edge thickness on the INFImandu back home was thick just like the one I have on me here. I have yet to see the SWATmandu that is waiting at home for me, so I don't know about that one.
None of the three of mine that I have actually handled has come with a convex edge. All V's.
Of the two, I like the SWATmandu better, although everytime I'm going on a hike out here where I'm det'd, I end up taking the INFImandu. Partly because of the thick edge. It seems to me it is more robust. The edge of the SWATmandu is, IMO, much more directed toward slicing flesh than that of the INFImandu.
In the hand, I can't tell a difference in the feel/thickness. The only difference I can feel is the grips of the SWATmandu are G10 and those on the INFImandu are micarta.
I'd like to get a few more SWATmandu's, just because I like their aesthetics better...