OK, we are defining acceptable triggers by different standards. 'Acceptable military trigger' is not the same as 'good trigger' IMO.
I have not seen or tried a Bill Springfield trigger, so I'll accept that it is better than the stock trigger by a good margin. As you note, original G3 specification stated that the rifle should not fire when dropped from a height 15 meters with the safety disengaged. I can recall outting a trigger gauge on more than a couple of HK91s and recording pulls weights as high as 18 pounds! Standard GI M14 run at about 6 pounds, with match triggers at around 4.5, two stage and a very clean break. There are both 2 stage and single stage triggers for the ARs. Most are drop in, requiring little more than adjustment. The M1A, FAL and (apparantly HK) requite the services of a gunsmith.
I did note that I have yet to see a G3/Clone place anywhere in any tactical rifle match I have ever participated in. AR-10 rule the 308 matches, with a few M1As up there. The people who shoot these matches frerquently drop $5,000-10,000 into their rifle/scope combos, so cost is not a factor. What counts is what wins. No HKs, sorry.
As another tip of the hat to the AR-10, it is by far the most modular, serviceable rifle. Changing barrels, stocks or even detail stripping is pretty easy. Headspacing an FAL or M1A is a bit of a pain. With the FAL, you need the right locking shoulder. Both the FAL and the M1A have times threads on the barrel. The HKs have a variety of methods to attach the barrel - from press fit to welding. I'm not sure what the clone makers are doing, but with an original HK, barrel change was a thought. My understanding is that the whole rifle was supposed to be replaced when worn.
My first G3 clone was an original HK 93. It had a high coolness factor, but I though ergnomics were horrible and was designed by someone who didn't know what rifles were designed to feel like. After shooting my Steyr FAL, it felp like a 2x4. I built a few dozen FALs, using STG58 and G1 parts kits, on a variety of receivers. I'd pick an FAL over a G3 any day.
In the search for accuracy, I soon tired of the HK and FAL, and bought an SR-25. Great gun, terrible customer service - unless you are a brancg of the military. I replaced it with an AR-10T and figured out an SR-25 is the same gun for much more money. I haven't tried the DPMS or Fulton AR-10 clones
I finally bought an M1A just to fill a hole in my collection. This was followed by a few more. The AR-10 is a more accurate shooter, but I ike the M1A. It works for me, and is a nice balance or accuracy and reliability, with a high 'club' factor to boot. I also already have an AR-15 and wanted something different. I expect to add another AR-10 in the near future - a dedicated semi-auto match rifle.
So my perspective on the various semi-autos comes from owning and shooting the HK, FAL, AR-10 and M1A. I happen to have a preference for the M1A for a 'do anything' rifle. This is as a civilian. If I were looking for a military rifle - particularly select fire - I might make a very different selection.
The above is of course only my opinion. I hope I have successfully explained my rational, without simply say 'rifle A is the best - period'. I donlt consider any of the rifles names superior to any of the others in a generic way. They all have their good points. And as I noted, I don't think the M1A rates 'number one' in any catagory. But I think it rates very good in ever category. For a do everything rifle, I'd say that's a good criteria.
'Jack of all trades, master of none'
That's just B.S. The HK91 trigger is quite easy to improve. I had Bill Springfield do my PTR-91. When I bought it, the trigger was long, heavy, and felt like dragging a lead sled across a gravel driveway. I sent it off to Bill with $45 and it came back less than a week later. There is no NO-takeup, almost imperceptible overtravel, and it breaks like the proverbial glass rod with about 4 pounds of pressure. 
