Who could hold a vendetta against you ta2zz? =P
Hmm, it's a tricky choice, both have good and bad sides.
Having an open chat does give new members another way to learn, however this can be done by simply taking two minutes and registering and making a post. Or even just read the posts without registering, that's what I did for a while.
There are other options for those seeking information, so I'd rather it be members only. Cutting down on the people simply out for annoyance would be a boon, in my view at least.