Hear hear!The FireFly has long been the gun of choice for my HvZ crew.... I wouldn't choose anything over the FireFly as a primary after seeing the Raider and other magfed guns fail to fire.
The FireFly always gets me odd looks when I pull it out for a round of HvZ, but I'd trust my brains to no other.
When dealing with zombies, the whole game changes. With no ranged ability to compete against, power, and to a lesser degree accuracy become unnecessary, all comes down to reliability and fast reloading.
Anything that uses streamlines is out in my book. If it can jam, it will, and usually just as you are getting bum-rushed. On that note, mid game darts become very scarce, and the ability to pick darts off the ground and use them is almost a requisite. Good luck putting a tagger or screamer into a Recon.
Perhaps a heretical suggestion, but a buzzbee berserker, may be the ultimate HvZ weapon. It adds pretty much all the benefits of the firefly, but uses 20 shots instead of 8. Could also contain a shotgun center blast, or a singled long range harassment shot.
Edit: Minor Necro ~1 week, but I've not heard anyone bring up the point about the Berserker being a valid blaster.