personally i love this, the dialogue is epic especially between nick and ellis and Francis and Nick at the end once just cracked me up:
"WITCH! oh wait, sorry, you confused me with all your crying!"
as for the M60, its hilarious fun, i just went onto the last map of the passing turned on cheats spawned a stockpile of M60s and went mono-e-mono with 5 tanks (i kicked the other survivors) lets just say that god mode helped
however the M60's main drawback is that it only has 150 shots, i mean...well yeah it keeps the survivor from going super crazy but not being able to get more ammo for it, haveing maybe 1 or 2 in the campaign, and the fact that 263 shots (approximately, i was left with around 40 after doing a tank 1v1 with the thing, and used 2 guns) are needed to kill a tank, really doesn't help, all this conspires to people hanging desprately on to the fun little gun which causes them to have problems with practically loseing one gun.
i would suggest to Valve that they add either: double the bullet carrying for the gun (300 rounds)
or: allow us to carry a second clip on the gun.
i dont want to get more ammo from stockpiles, its like a grenade launcher, you get what you get, but it just seems to need...more to me