Len,
I just sold a blue S. Haddoni carpet that I'd kept for about 4-5 years. In the time I've had it, I lost two fish to it.
A mandarin and a possum wrasse.
While I kept the anemone, there was also a red flame hawk, a purple tang and a blue damsel in with it. These fish lived peacefully with the carpet in my 120 gallon reeftank.
One observation, and one that another carpet anemone owner has also noted -
If possible, place the carpet close to a vertical rock wall, so that the oral disk is not lying flat on the sand/substrate. If the carpet is allowed to lay flat, I think (can't substantiate) that fish can't see the predator to well and end up getting too close. I have a pic of the orientation of my carpet posted over on the BRS website. I'll pm you a link so you can see what I mean.