These four adventures are anything but simple and are indeed a min-campaign in themselves. Check out this thread over at DF:
http://www.dragonsfoot.org/forums/viewtopic.php?t=17881 You'll find some interesting things about them in there. Personally, I'd love to play them one day - but then I'm a big fan of Rob's writings, so this is really no surprise :smt001.
I especially like the second and fourth adventure. Both are excellent and among Rob's best. The first one is pretty good too, the only weakness lies in the third one IMO. Although a fascinating setting with lots of interesting detail, I find to be simply unplayable as written and it therefore needs quite a bit of alteration.