I run a 7bbl brewpub in upstate NY and I've filled growlers with a homebrew counter pressure filler with great results on quality and beer loss (as in NO beer loss). Those growlers went out to local stores with great shelf life (6 months on filtered beers). I got our filler from foxx equipment for like $70. It is already setup for pry top bottles (12oz, 22oz) and with the purchase of a slightly larger stopper it is retro fit to do growlers. I highly recommend it for cost effective, clean, oxygen free hand bottling. And it wasn't too time consuming either. I could fill 5BBL of growlers in an eight hour day including setup and clean up, completely by myself. The bottles were pre cleaned and sanitized though. I say go for it!
Plattsburgh Brewing Co.