I would give Goodman DCC's a shot if they were written for 3.x or pathfinder. My group had played through a couple when they were being made for 3.x and found them to be enjoyable. we never tried any of the 4e ones as we were finished with the system based on its own merits and flaws before we really got a chance to start exploring 3pp material.
I would suggest to Goodman to try and release a new single module for 3.x Pathfinder (or whatever system you are thinking of trying) and see how well it sells. If it meets the needs of your company financially then do more of them, if not then stick with whats working now.
But thats just my own opinion, and it is the opinion of a gamer, as opposed to some of the other opinions posted by other members of the industry in this thread.
love,
malkav