Russ, it's not based on any in-depth knowledge of the various harbors along the coast.
I looked at both harbors about 4 months ago and at the time the Pass harbor did not have pump out services, while Long Beach did.
I'm at Pass Harbor... I like that it's a bit closer to home (Slidell), and it's "close enough" to the islands.
There actually is a pump-out station (it's right next to Shaggy's), but it's not that simple. I inquired about using it once, and was told that boaters weren't allowed to use it themselves... a designated harbor employee had to come do it. Ok, so I tried to make the necessary arrangements, and after a few back-and-forths on the phone I was told that a hose adapter or something like that was needed, and they couldn't find it. I think the message was pretty clear... there's probably some law that requires them to have a functional pump-out station, but "functional" I guess is pretty loosely-defined.
The harbor seems to be VERY jumpy in terms of calling for mandatory evacuations for storms. Actually, I've heard it's the fire chief who makes the call (the fire chief!?!). I've had to move the boat inland twice in as many years... Ida last year, and that weak tropical storm that came in a month or so ago. The itchy trigger finger for minor storms is really annoying. But at least the close proximity to Bay St. Louis speeds up the process of moving inland... from Long Beach or Gulfport, it's a much longer trip to Bay St. Louis or Biloxi.
Anyway, we didn't get out much this Summer. Though BP is largely to blame for that, it's not all their fault... I spread myself way too thin this Summer in terms of work, leaving little time for anything else. I'm making a conscious effort to not do that again next year... time on the boat is the best "together time" I have with my family.
On a brighter note, we made it out this past weekend to Ship Island. Saturday night we had 2 or 3 neighbors (it was a gorgeous afternoon/evening, but a stiff NE wind started blowing after midnight that made for an unpleasant night). Sunday there were probably 30 or 40 boats out there (maybe 6 or 7 sailboats, the rest small powerboats), with a handful remaining overnight.
We had a great weekend!
--Michael