There are so many factors that go into military contracts. It's not as simple as "this shoots better than that" or "this has this unique capability." DT has had a number of military contracts for the SRS over the years with foreign militaries, but the scale of those contracts tend to be fairly small, from what I understand.
Some of the factors that helped the MRAD and hurt the SRS:
- Barrett is a manufacturing powerhouse with a proven track record while DT is comparatively small
- MRAD is a traditional action soldiers are used to; SRS is bullpup
- Magazines have always been the weak link with the SRS
- Program requirements change over time and I think in the past DT hasn't been nimble enough to match them
- When things go wrong during trials, it's almost impossible to recover
So it's a complicated topic, but nothing to necessarily fault DT for.
As for shooting both, the MRAD is easily Barrett's best rifle across a variety of factors. Personally I still prefer the SRS (I have two and have been shooting the platform for 15 years), but if I was still in the Army I'm not 100% sure I'd want to run one. Sure, I would prefer to hump/jump a Covert over a standard bolt gun any day, but actually fight with one? Hard to say. I can run the bolt faster/easier with a standard rifle, and yeah the mag issue would bother me a bit, so I don't know.