I also have frozen butter, although I'm not sure that I can really attest to how well it works. I seldom use butter direct (say, on bread or toast). Most of my use is for greasing baking pans, or sometimes cooking. But I've had no complaints with frozen butter in the ways I use butter.
I don't keep butter out of the refrigerator, but I have known people who do and report having had no real problems. From a view of human history, refrigeration is a new idea. But I, myself, feel better keeping butter cold, even if it's harder to work with.
The value of freezing butter is probably one of those variable things--how much butter one uses, and also what local market conditions are like. Since I live alone, and don't use butter much, freezing is essential. It may also be a huge cost savings, since I tend to be a bit picky with dairy brands I buy. But if I used more butter, and was not particularly picky about the brand I used, freezing might lose value. It seems like some cheap brand is always on sale some place here.