I agree, the FS knife is a good fighting knife, but not so great for just about anything else. It balances well and can be thrown with little practice (but throwing a knife is rarely a good idea). The blade is long enough and balanced well enough that it can be a good slashing knife even though the foil style handle is less than perfect for slashing attacks. As a stabbing knife, it has few peers and is truly excellent for the job. So I rate is as a good fighting knife.
Personally, I see fighting knives and utility knives so incredibly at odds, that I just can't abide the concept of a general purpose military knife. I really like the M4 & M6 bayonets because they make a good fighting knife, and a competent bayonet. The pommel is tough as nails and can be used for many pounding jobs. The blades are generally very tough and hold an edge well once you get one established (getting the edge established on an M4 or M6 bayonet is a cast iron pan in the arse though). Since the M6 is Fairbairn-Sykes - esque, it's a good fighting knife, just poorly balanced with too much weight in the pommel. Still, slashing power is decent and thrusting is excellent. The blade is thick and sturdy, so you don't have to worry about the broken tips that plague most purpose built daggers like the Fairbairn Sykes.
For most everything else, a good multi-blade folding pocket knife is the ticket. I've always been a huge fan of the Victorinox Swiss Army knife, but I'll admit their blade steel is less than stellar. The blades are ductile enough to avoid breakage, but they easily lose their edge. If a Swiss Army knife is to be carried, one HAS to have a sharpener available or the knife will quickly become useless.
If I were a young buck fighting in foreign lands, I doubt I would choose the FS as the knife for me. I would probably seek out an M6 bayonet for my M16, a good Swiss Army knife and a $2 Smith's Wal Mart Special knife sharpener like this one:
The little Smith's knife sharpener is a gem. No, it doesn't give you a perfect razor edge, but it comes close. Most importantly, it sharpens very well with very little effort and takes absolutely no skill to use. The carbide side will put an edge on an M6 bayo or any other blade for that matter, and then the fine ceramic sticks will hone it to a rather sharp edge; wonderful little device.
Finally, a good multi-tool such as the Leatherman is always a good idea, but I'm not aware of any multi-tool that has a truely excellent quality knife blade. Still, my Leatherman Wave has a lot of functionality and blades made of 420 stainless. 420 isn't the best stainless in the world, but it's certainl not bad, and I'm not aware of any multi tools with better blades (I'm sure they exist, but when I bought my Wave several years ago, there weren't any better).