Are you planning on playing a campaign in Hyboria? Or do you want it for the system to do something else?
If you want to play a Conan campaign, then there is no substitute and the problems with this edition are superficial. If you want it for other things, then maybe you should steer away.
Caveat: I love the game. (edit: And I recently discovered I was thanked in the credits for the Atlantean Edition... humility aside, I don't know that I deserve it, despite my efforts to help on the message boards resolve the problems with the first edition.)
Comments:
Combat is a tad more complicated than D&D. But it is not complicated and once you have run it a couple times, you realize that it simply adds some elements to D&D but not so many as to overwhelm you. Be mindful, however, that the first session you will feel a bit overwhelmed, but by session two or three combat will run much more smoothly. (A hint for new GMs -- although characters have the option to Parry or Dodge for their defensive AC, 95% of the time they will do one or the other, so ask them which they prefer to do and force your PCs to tell you when they switch to the other. Asking every round what they are doing seems like a good idea at first, but bogs things down and is invariably pointless.)
Now, here is what seems complicated (although, again, you get used to it and it ceases to be difficult) about combat. Armor serves as Damage Reduction. Weapons have Armor Penetration scores. If the AP exceeds an armor's DR, then it halves the effects of the DR for a successful attack. If the AP is less than the DR, then the DR is in full effect. Sounds complicated? Yeah, but it isn't.
Sorcery... it works and it has a Howardian feel to it. In that sense it is a good fit for CONAN. I still find it a bit clunky and would prefer to use a different low magic system. I got around it by not letting any players start out as spellcasters. As it turns out, no one ever picked it up (and the only player who was keen on it dropped out early for family reasons). Sorry I can't be more specific. I just don't care for it.
The details of the setting... I have to say, the reason for that is because they wanted to stay true to the source material and Howard did not fill in many details. The supplements correct this problem -- which is really only a problem if you are not willing or interested in creating details yourself. For me, I liked having freedom to say "here is a town and here is its place in the politics of this land" without having someone tell me that it does not jive with the sourcebook.
Typos... c'mon. Conan has a bad rap because the first edition was so TERRIBLE. And it was terrible. Are there typos and other editing mistakes in the Atlantean edition? Yes. Industry standard stuff. Not that that is not a crime. But I would say the book is up to industry standard in this respect and so no better or worse than any other.
I'll see if I can come up with anything else that bothers me about the system.