First a little background. Sometime or another in the late '80's I discovered Frank Mentzer's BECMI. I love collecting games and reading them, even if there is little chance I'll ever play a given title. The Larry Elmore covers, especially on the BEC boxes, were awesome to me (they still are).
The group I played with was very anachronistic. You couldn't turn a page without finding something that had been house ruled. This was done on a foundation of 1E AD&D, and later a mash-up of 1E and 2E. Pretty much anything went when it came to characters. No level limits for demi-humans, humans could multi-class, anybody could use weapon specialization, etc, etc, etc.
At some point in time, I decided I wanted a simpler game. Originally, I wanted to play AD&D as written and just see how it would work if played as intended. I didn't get any traction with that idea. So, since my exploration into a simpler method had officially become my personal mental exercise, I figured I may as well go all the way. Immortals didn't really interest me, but I loved BECM. I did not hesitate when the Cyclopedia came out. The idea of such a complete version of D&D for (then) $25 was attractive enough. The fact that it was the collected BECM was the cherry on top.
Late in 1992 I gave my copy of the Cyclopedia to the son of a friend.
I don't remember exactly when I learned of Dark Dungeons. I received a print copy via Lulu about a year and a half ago. I haven't read it as thoroughly as 18 months allows, but I do like what I've seen. There is an extensive list of changes between the RC and DD, but they are almost exclusively limited to clarity issues.
Anyway, this isn't intended to be a review of either title, or a compare/contrast piece. It is just some thought on some things I have read on the web concerning them. Pretty much anything that applies to the RC applies to DD by extension, so it seemed logical to discuss them together.
One of the biggest knocks I see against the RC/DD is that it is too complete. The perception is out there that it includes rules for everything, thus removing the game from the DM and putting it in the rule book, a la 3.x or Pathfinder. After spending some time with my RC pdf, and DD, I don't see that. Yes, there are more rules for things that commonly come up in play. I think, though, that the extra heft in the books comes from subsystems that are very specific. For example, pages 169-194 of DD are chapters covering mass battles and immortals, topics that will be a long time coming in campaigns beginning at 1st level.
There is also a lot made about the rules covering character levels up to 36th. Many players prefer a shallower power curve. I myself have discussed that very thought. Upon further reflection, I can definitely see where a longer power curve can bring something to the game. With a 36-level spread, I find it much less troubling to assign levels to special, yet non-pivotal, NPCs. A captain of the guard could be 6th level, which allows him to be accurately represented relative to those under his command. With a 14-level curve, the same captain would probably be no more than 4th level, probably 3rd. That doesn't leave much room to represent the lieutenants and sergeants in his unit.
So, that just a couple of thoughts on these two rules sets.