since i own both now , and use both (i like the bar to troll XP and yea i bought it with real money, want to fight about it?) , i must say BAR has its disadvantages, the freeze is enough on a bar for a skilled M4 or sten user or even dual eagles to compete with, its true, i actually feel disadvantaged in some cases with the BAR compared to when i was only using M4. each gun has its own advantages and disadvantages but i will say this:
if anyone plans on nerfing bar they better refund me half of what i paid, and also decrease the price as well for future users.
i really found it isnt as all cracked up as i thought it would be. the real difference is the ability to spam doorways in bases and mow down people, thats all.
an upgraded M4 is 9 damage, and upgraded bar is 10. i still feel better with an upgraded M4 then i do with a bar.