Yes, I have and I would do it again.
The El Capitan Theatre here in Hollywood does a Pirate Marathon now when a new Pirate movie comes out. I have now attended two of them, once for #3 and then again for #4.
It is so much fun, I can't even explain. I go with my gaggle of girlfriends, and we pack a backpack full of candy. The El Cap does it up really well, we get breaks, and they have us eat between movies out back and they give us food and ice cream and stuff.
They even had some of the Pirates from the movies show up. THAT was awesome. Poor Norrington, we screamed like we were 15 when he walked out on stage.
For the last one, they even gave us a bag and some special Pirate pins.
So, yes, go, and have fun and enjoy yourself. I can't wait now for POTC #5 to come out. We might have to get a hotel room nearby for that one!

(Oh, and I am 44 years old.)
ETA: At the El Cap, the seats are purchased ahead so you have assigned seating. This is the ONLY way I'd do a marathon instead of having to live with some random assigned seat.