Barrett has a .416 rifle though which Warz may have been thinking about.
http://en.wikipedia.org/wiki/.416_Barrett Basically it is an alternate chambering for their model 99 rifle.
http://www.barrettrifles.com/rifle_99.aspxThe palm pilot computer is something Barrett is developing to use with ALL of their rifles... it was orginally shown with the 416 I think though.
As far as the recoil sucking, I have seen many videos and read reviews about it being nice. The article fromt eh OP is the first instance I have seen of where it is a horrible hard to handle rifle. Even Barrett's site says it is nice, more of a push than a kick, but good for even a novice.
http://www.barrettrifles.com/faq.aspxQUOTE
What does .50 caliber recoil feel like?
Much of the recoil in both the .50 BMG and .416 Barrett is reduced by the muzzle brake. The main spring and the barrel springs in the 82A1 reduce the recoil even more. Our large caliber rifles all weigh over 20 pounds which also helps to reduce recoil. While this is a very frequently asked question, even novice shooters do not find the recoil to be objectionable. The "feel" is more of a rapid push than a sharp kick.
Here at work I cannot look at youtube and the like (damn DOD blocking so many sites

) but if you look up the m107 you will find many videos showing the operation and the relative lack of recoil for a weapon that size. Futureweapons did a show on it and showed the guy firing off 10 rounds in less than 10 seconds.... not too shabby. Granted he is an ex Navy Seal, but still it is obviously easy to handle by us mere mortals.
As far as runners not needing something like this.... BS
The US military started using these rifles in Iraq heavily outside of their original Anti Material role in an effort to better deal with entrenched enemies in Urban Combat situations. Enemies in a building behind multiple layers of concrete can seriously deflect or stop smaller rounds making it harder to engage the targets. The .50 BMG will pass through those things with no issue and still have the energy to drop the target.
Runners would have similiar uses for the rifle. That person will not have a safe cover angle when the bullet goes right through the small car they are standing behind. Throw in the radar cyberware and you can shoot through walls without them even suspecting it.... sounds very SR to me.

The game has the equivilant of the 107 statted in arsenal... the Barrett m121. IIRC it does 9p with -4ap... so better than the standard sniper rifles. Load it with APDS and you have a serious monster. The image in arsenal even shows a picture and it looks similiar.
The M109 would be a good real life representation of an assault cannon. The picture of the Ares Assault Cannon in arsenal even shows it looking like the 109. Assault cannons do 10p -5ap... more than the 107 so I think the scale is correct.