I can't say I love it or hate it - I'm kind of in the middle. It works, although not miraculously, when used with proper dieting and cardio. I get most of the negatives, too, including elevated bp, headaches, shaky hands, and cramps. I don't buy the theory that it's anticatabolic at all. In my experience, you will lose muscle if you're not taking it alongside AAS. My body also seems to adjust to it very quickly, even with benadryl (I haven't tried ketotifen). I do better with 5 days on, 5 days off than I do with 2 weeks on, 2 weeks off.
It is definitely good for one thing. I'm getting over a case of bronchitis at the moment and a small dose of 20mcg really helps open up the airways!