From: El Paso, TX
Which means the experienced human player has to face an "Ironman" level AI opponent in order to have a challenging game. The new AI does far fewer "stupid things", and so it's better, but against a human player it all comes down to "more stuff". The more it has, the more the AI can do, and the more leeway it has to absorb what would otherwise be crippling blows if received in Scen 1 or 2.
With my regular playing against Ironman I now believe that in some cases it can be too much quality, not just quantity. E.g. it is mostly pointless to wage offensive air war against Ironman Japan - you have no hopes of denting AI forces in exchange for your regular bloody nose, and AI is everywhere. So the game becomes more trivial - you can only capture his air bases via land campaign, or bombard them to oblivion from the sea. Bombers become essentially useless in their primary role.
Not to mention regular Sydney vs Kormorant encounters that are even more one-sided than the real thing
Which level of Ironman are you referring to, since there are 3 for the Japanese AI? My current game is Scen 102 (Ironman 1 test version), and I find that bombers are quite effective. 2Es must fly at night, and while 4Es can survive day missions, the heavy attrition keeps most of them working nights as well. The AI does have a lot of good fighters and pilots, so there's plenty of bloody noses to be had, but well trained Allied pilots flying defensive missions can - just barely - stay ahead of the curve. The airframe losses are significant, but I actually like the fact that you have to ration out the replacements. As for those killer AMCs, yes that was a shock the first time they tore up a light cruiser TF, but hey? Once you know they exist, you operate differently.
In early 1943 I'm dealing with brutal air and jungle warfare along the Indo-Burmese border, a meat grinder in the Solomons, a slowly losing situation in China, and the opening moves of the Central Pacific atoll-hopping campaign. Against an opponent that is still deadly and dangerous, with most of KB alive, hidden, and biding it's time. What's not to like?