I just wanted to add that I thought you had to switch pellets slowly and transition like dogs, but it turns out you don't. The only reason you have to do that for dogs is because they will throw up. Guinea pigs can't throw up, so they don't need the transition. They transition really well with almost all food without any mixing of any sort.
When I first got Oxbow, it was right after I ran out of pellets so I just gave my pigs some and said "well here goes nothing." They weren't hurt at all, the only change was they loved it and ate it really fast. The only actual hassle is buying the food and taking the time to put it in their bowl. Boom, you're done.
FINE YOU ALL CONVINCED ME!
I WILL SWITCH TO OXBOW (if my parents let me)
So overall pros for oxbow: Healthier, most pigs love them, can be cheaper when you buy in bulk, timothy based for adult gps, lower calcium to avoid bladder stones (you'll pay much more for surgery than a bag of this), recommended
Cons: Sometimes people think it's a "snooty" brand and are reluctant to switch, if you buy smaller bags it's more expensive (but sometimes lasts longer)
Pros for your food: Cheap, your pigs are used to it, you like it
Cons: Alfalfa based (should only be used for pigs 6mo and under), only sold at the pet store you are boycotting, overall unhealthier
Just a thought, you know? Maybe you should consider switching.