Hi,
I used 4 of these (3 new style, 1 old) for about a year when I first got into brewing, in lieu of bottling. Here are a few pros and cons from my experience:
Pros:
- Easier to sanitize, fill, and store than bottles.
- Portable! Take it with you to work, church, or a wedding!
- Fits in standard fridge and most mini fridges.
- Durable. I never had a problem with leaks or had to replace the original gasket.
- There's just something cool about drinking beer from a pig.
Cons:
- Price. For a five gallon batch you'll need two, which is $80 up front. For each additional batch, you'll need pressure pouches, $4 a piece. This adds $8 to the cost of each brew and is more expensive that CO2.
- The activation method is a bit screwy. You have to hold open the valve while pumping air in somehow, they sell a hand pump for this purpose. Most times it took about two dozen pumps to pop the pouch, but there were a few instances where I had to use my foot, and even then once or twice it blew the check valve out of the end of the pump before the pouch activated. If you have some source of CO2 this can be avoided, but then again if you have CO2 it's a moot point because you might as well keg.
- Once the pouch is activated, you can bleed off some of the air, but inevitably there will be some oxygen left. There's debate over whether the yeast just consumes it or if it affects the flavor of the beer. I was too green to tell the difference I suppose, my beers always tasted good to me!
-After depleting the pig, you have to manage to remove the valve body which is attached via a steel collar with 4 screws. The pressure from the fully inflated pouch makes removing the screws evenly challenging. Some poeple advocated only partially removing it and popping the pouch with a knife, but I found this tends to chew up the plastic on the valve body.
- Dispensing pressure can be fairly low, particularly with older pouches. I forget what the company claims, 15-20 PSI I think, but it's more akin to dispensing from a keg at 5 psi or so. This wasn't too much of an issue for me, though sometimes a line formed at the fridge.
On the whole, I found the pig to work pretty much as advertised. It was easier than bottling albeit perhaps slighty more epensive (particularly if you're a bottle scrounger). I gave mine to a buddy new to the hobby after I built my kegerator and they're still serving him well. Just do yourself a favor and try and find the newer style pig (blue button on the valve assembly and 4 legs on the tray), it was a lot easier to pressure and you don't have to align the grooves when putting the valve body together. Hope this is of some help to you!
Oh an by the way, give SWMBO some warning before trying your hand at popping the pouch. It sounds like an M-80 going off indoors if you don't take the "pinhole" approach, trust me on this.