Bingley has naturediet, he loves it. We have started buying it by the case as it works out much cheaper (about 14 pounds for 18 trays), so this may be worth considering if you are going to be away for a while.
I know they did have a problem with blown trays at one point but i think they've resolved that now. As others have said, you have to store in a fridge once it's opened. I would recommend it, we use it as Bingley went off raw a while ago after wolfing down a chicken wing and making himself a bit sicky. It is a good alternative i think. He looks great on it and his (usually sensitive) tummy has been fine.