The problem with adventures is that they involve a lot of stats and maps. That's really time consuming and tedious. Oh and you have to pick a system. And a level range. And conversion is even more time consuming and difficult. Think about how different battle maps have to be in 4E than 3E. There's a lot more movement in 4E for instance.
Of course, If I had more feedback on the first two PDFs, then that would help. What do you use - what don't you use and why or why not?