While they overall weight doesn't seem all that heavy, it's not exactly comfortable to hump because all the weight is in the barrel. The rest of the gun is pretty much a hollow shell for the parts to bounce around it (a factor inherent to it's less than awesome accuracy). Also keep in mind that a full 10 round magazine weights about 10lbs too.
I'm going to have to heartily disagree in the similarities of carrying a SAW vs SASR. I humped it for our team and tried a couple different methods.
The generally accepted method was to break it down into it's two major parts, which basically was a 25lb upper and a 5lb lower, and pack them in a ruck. Dual Kifaru Gunbearers helped immensely in this regard. Four magazines were packed and it was assembled once established in your FFP. For security during movement, you still used your M16A4 and it's general accouterments. This was usually a AN-PVS14, 7-13 magazines, ACOG, PEQ2, rails, grips, etc. Now throw in enough water and food to keep you functional throughout the mission, the "command required" body armor, and various other mission essentials and your a hurting man.
Because of circumstances specific to our team, I needed to carry the PRC-119F radio as well. Our typical distance from friendly units required me to build our own antennas so I needed about 200 ft of 12ga speaker wire and some other radio shack parts (collectively called a FEAK), and one spare battery a day. All this stuff together meant for a quick and dirty 3 day mission, I was humping my body weight in equipment.
Spread-loading your equipment throughout your four man team is best, and we did. However, it was too much weight for me to remain combat effective. We often grabbed an eager young buck from another unit to tag-a-long near me to cover my security area on patrol. I stopped carrying my rifle and dropped a strap from the top of my ruck over my shoulder to carabiner to the front sling attachment point on the SASR. In my HSGI Wasatch I doubled the width of the magazine slots by cutting the divider on every other. I loaded up one magazine in the gun and carried three more on my chest.
It still took all my attention to man the radio while rucking that much weight and managing the rifle. It was a handy boomstick to have ready in the case of chance contact, but it limited our quick maneuvering options as a team. That's why it was better to take an extra man so I could focus on not being a liability more than trying to be vigilant as well.
To sum it up:
If I could afford it, I'd like to have an airsoft Barrett SASR. If you are going to field one for a game though, bring an extra man because it is an unwieldy weapon system...unless your a giant, but snipers usually aren't. If you usually roll alone, hook up with another lone sniper and leave the fieldcraft to him. If you usually have a sniper/spotter team, make it a trio. When you carry the SASR, your concern during movement is to not draw attention to yourself. It's tiring and you'll get tired quick.
It's also very hard on your back. For me, having the radio made it heavier over all, but it was worth it just for a counter-balance.
My honest opinion though is that this rifle is probably going to suck nuts. The real Barrett isn't a sniper rifle and this one won't be able to compare either. I have an inkling they are throwing a AEG gearbox in a Barrett shell and calling it a sniper rifle. My best hope is that it's at least a PSG-1 cloned box with a fair amount of aftermarket accessories.
If I were designing the rifle, it would fire 8mm BB's and would need enough power for a minimum engagement distance of 75 yards. The SASR is intended to be the cannon for the long range shot on a "hard" target. I would appreciate it if the airsoft version would embody that.