I haven't seen enough in PSA to make me want to do anything in it. Maybe its just my experiences, but the people i've met haven't really impressed me all that much. Lots of "look at my bad assed dog" attitudes and very sloppy training. that may not be the norm, so take it for what its worth.
As far as something similiar, I do Schutzhund and Mondio, no titles in Mondio for my dogs, but I do decoy for it. I think the trainers and dogs are much better in those venues for the most part, although i have met a few that have played in both PSA and MOndio that are very good as well.