The gems is a great idea but out of my reach at the moment. I was able to get one awhile back and was saving to get another when ROK II came along and I started using up all my FP to resurrect my character. *sigh*.
I just activated a gem. Its a lot of work to get one so you have to make sure you are investing in a character that you want to keep. The first gem gave my character an unusual twist so I tried to activate a second one but found I needed even more core posts so its definitely reserved for someone who isn't just passing through.
Yes the gems are a nice thing to add to a character. There is enough play in them that you can be surprised on the outcome. It does make the character a bit funner. But yes you will want to save the gems for a character you really like.
Thanks for the clarification JB. Are the gems geared to your character. I know they are random. Say I have a character that is terrible at ranged weapons or can't use long bows. Is there a possibility of getting a magic weapon that my character can't use?