Justin,
I had the same experience you had. I saw a flower pot at an lfs and asked the guy if they were hard to keep. He said "NO, if you can't keep one of these, you can't keep any corals"! I bought it, like a fool, and it was dead in two weeks.
As everyone else has said, they are very difficult to keep and have them thrive.
ChainSaw,
I bought a Hammer about 6 months ago....it had been returned to the lfs by someone who had let about half of it die off so I got a really good price. The best advice I got was to make sure my calcium level 400-450 ppm. Good lighting helps too, of course. My hammer is thriving....lots of new growth.
Jim