I've only been on them for about a week, but the weight loss doesn't balance out the side effects. I am always warm, thirsty, and I've been getting a lot more heartburn and headaches than usual. Depending on where you read, these "mild" effects eventually dissipate the longer you're on the pills, but for some people they're too much to sit through, and I might be one of them.
I'm cutting back to only one pill a day, which should help. Overall I think the ketones are still a viable option for some people. They did do something and I might stick with them for a bit longer.