I have the clipper stainless, and it's a very good general purpose knife but has a half-tang so not strong enough to be hammered into tree-trunks, used as a chisel etc. I only use my MOD for chopping wood, as it's quite heavy; too heavy to carry around every day; and arrives fairly blunt (suggesting that it isn't meant for fine whittling etc). I would go for the clipper first, and only get the MOD if you need some serious chopping doing.
I've used both. They are both very good knives, but as pointed out above, quite different. The MOD knife is great for chopping wood and suchlike, or even digging a hole, but would be pretty useless for skinning a rabbit.
The clipper is better for any sort of precision cutting and is easily made sharper than a sharp thing. I couldn't comment on it being used by THEM , but I gather that it is issued in the Swedish Army and to UK Forrestry Commision Rangers (for gralloching deer). The best thing about it is that it is cheap as chips. You can buy 3 or 4 for the cost of a MOD survival knife. It's also a lot lighter!