D20 does have a bit of a crunchiness to it, more so than some systems and less so than others, if I would put it on a scale from 1 to 10, with 1 being less crunch, combat resolved by ROCK, PAPER, SCISSORS and 10 being really crunchy aka ROLEMASTER, it would rate about a 6, IMO.
The problem with D20, is it is easy to become bogged down with rules and such, which is one of my problems and why I choose Conan in the first place. Plus rules lawyers are a plenty in the system. Part of the reason, I went to other systems, I was tired of people arguing with me on the rules when I am DM and slowing the game to a crawl. But as always, time has a way of changing things.
The group I game with has litterly everything that WoTC has put out for DnD and I am not kidding. The current campaign that is finishing up, before I take over as DM, I am considered strange for only have a base class, Sorceror and one presitige class, Elemental Savant. The rest of the group has an average of 3 classes, most of them not even from the base book.
I was told that I would need to run d20 game of some sort, if I was going to take over as DM. So, I concided. I decided I wanted a version that would limit the group, so I was deciding between Iron Kingdom and Conan. I gave the players some chance to voice which one they wanted and one of them said, "Do Iron Kingdoms, it gives us more options." So I choose Conan.
Granted they are already trying to get me to allow classes from other D20 books and I am pushing back. I may allow an occasional feat or something like that, but I am trying to avoid presitige classes. Hence my thread about drunken master.