I love drinking it but it is $$. I've read about many people making their own but I'm a bit lazy and I've also read that you should be very sterile in making it.
Is it helpful? Well it has some probiotics which are good for you but anything it offers you can get elsewhere. So if you like it and want to splurge on it, drink it occasionally. If you think that it is some magical elixir, then I'd say skip it.
You can't out-exercise poor eating habits.