Tagging along. I lost a small niger, and was a little apprehensive at first. Hate I lost him, but, wanted to know if they get aggressive as they grow like a Damsel that can do much more harm...
My LFS has a 7 or 8 inch in a 200g tank with clowns, chromis, snails, and a large angel with no problems. I guess it may depend on the personality of the particular trigger, tankmates, and tank size as with any other fish...
Oh yeah, feeding them well is of utmost importance, like PFCDeitz said...