Deus Ex's AI was so painfully bad... and the enemy moved so slow.. it seemed clear that they were trying to appeal to the RPG gamers who were not quick with the mouse.
Guess it depends on how you play. I usually opt for the stealthy approach, as the straightforward approach is usually too easy. The weapons I used most were the baton, the stun prod, the mini-crossbow and the dragon sword. Combat AI isn't much of an issue when you kill your enemies before they know you are there. Their awareness AI wasn't too bad either. You could use sounds to lure them, which came in handy.
As for your labeling system, I think you mean to say that you want a true RPG Action game. An action RPG is an RPG with action elements (Bloodlines), whereas an RPG Action game is an action game with RPG elements (Deus Ex). Unfortunately, I don't think a true balance between action and RPG will ever be possible, since stats play such a fundamental role in RPGs. If you make the action too skill-based, then stats will be irrelevant. I thought that Deus Ex made a nice compromise by having stats affect how long it takes your reticules to focus.