The AWS has one thing over the MG4 and it's ease of use. What attachments were you using for the MG4? Also were you moving and shooting at med-long distance and were you tap firing?
I tried the LSAT again for a bit and holy cow it was like a laser beam (tat, tat, tat dead). I may have to try it out more. I'll probably be playing more support than usual and try some other guns out as well.
Edit: two things faster reload and what I mentioned above. It's a variant to the m16 class so it's more in line with ARs and AR suppression model. It is definitely a good gun, however, I have different opinions than the top YT peeps. I think the AWS is overused but not the best.