[tor-relays] Usefulness of very limited exit policy nodes?

Hi,

Opinions please - is it worthwhile running an exit node on a home DSL connection with limited bandwidth and exit policies? I'm talking 150Mb per day, 20Kb/s, and only allowing ports 80, 443 and 53 out. I'm concerned about potential abuse from exit traffic more so than limited bandwidth. I've only had it up for a few days and the bandwidth is being used.

Is such an exit policy useful for the network? Or would I be better off just running as a relay? Are there other ports that I could allow to exit that would make this node more useful, while not greatly increasing the risk of abuse reports coming my way?

Phil