IIRC, the "sustained" rate of fire was 6 to 9 round bursts on both. so swapping out the SAWs for a lighter MG with 100rd drums would NOT affect that capability too much.
Yes, I remember the "I need a burst" quote when you fire it to keep the firing rate low.
This new rifle fills a role that is technically already filled, the M4A1.
I never carried a SAW on a patrol, but yes they are heavy. I also remember the locals in the Balkans say that people were afraid of the SAW because of its size and appearance. I love that physological edge right there, and hell 800 rounds coming out of one spot doesnt hurt either.
But I'll tell you what, if you gave an excellent shooter the M27, I could see how it would fill a niche of rapid well aimed fire for a squad to have as opposed to supressive fire that the SAW provides.