Season 4 and still Sunny

I recently purchased and devoured season four of ALWAYS SUNNY IN PHILADELPHIA on DVD. The show is in fine form throughout the year, as there isn't a stinker episode in the whole bunch.
In particular I'm fond of the "Night Man Cometh," which revolves around a musical Charlie writes to woo his love, who is simply known as "The Waitress." This by far the wackiest episode ever, and that's saying something.
"Night Man Cometh" is also the inspiration for the best (of the limited) extras. The gang put on a live expanded version of this episode, which is on the DVD. The episode includes extra songs and offers a personal feel that kind of freaks me out.
The extras are really disappointing for this season, especially considering all the extra content that is available on HULU. I thought at the very least they'd repackage some of that stuff for the DVD, but instead we're limited to the live episode, a story from DEnnis Reynolds' erotic life and a blooper reel that isn't long at all.
Luckily the episodes are so funny that I'm not too bummed about the lack of extras. I would recommend buying this season if you can get it for under $30, which you can at Amazon. Also, watch ALWAYS SUNNY now, as it is currently in its fifth season on FX.