I was trying to make the same decision a while back, I went with the M1A. In my case I went with the SOCOM 16 but if I had to do it over again I would go with the Squad Scout for 2 reasons. First you don't lose as much muzzle velocity (although my 16" barrel has a .308 delivering as much force at 200 yards as a 5.56 round leaving the barrel) and the SOCOM front iron sight is too thick for my taste.

That being said the M1A needed a lot of work to be as ergonomic as the AR's I am used to. I went with a Vltor stock and rail system which gave me better optic and accessory mounting options and more importantly shortened what felt like a very long length of pull and best of all allows up and down adjustment for stock height so I can finally get that perfect check weld.

I upgraded the piston and forged bolt group (had the head space and timing checked) as well as the best bang for the buck mod in my opinion which is the Sadlak spring guide rod (this should come stock!). I went with the Micro T-1 so as not to add more weight to an already heavy weapon and it had the lowest mounting profile I could find. Lastly after this picture I went with the MagPul MS3 sling and finished the custom trigger job.

Bottom line I love this baby but probably spent as much in mods as the rifle was to start!