I enjoyed Action 900 alot. I was a bit hesitant to buy it because I haven't been reading Action Comics prior to this, and the whole Doomsday thing had ties to this book. But i went for it anyway and really enjoyed it.
My problem with the main story may stem from the fact that I didn't really know what was going on prior to reading this issue. But some of the pacing felt a little off, like with Lex suddenly achieving infinite power almost instantaneously with only a slight, not very dramatic build-up. Was there more information about this established in prior issues? Because i'll probably go back and read all the previous books. And the other thing I didn't like about it was how the Doomsday stuff was cut into it. I felt that, despite being a chapter in a larger story, the Superman/Lex story could have stood on it's own as a great story about why Superman is such a great hero. Throwing in the Doomsday stuff really cut short any poignant moments. The Doomsday stuff should have had it's own section to the whole issue, rather than being intercut with the Black Ring stuff. That said, I think i'll add Action Comics to my pull-list now, especially if this is the quality of work that Cornell has been serving up on this title. The back to back quality of Action Comics and Detective Comics would make this part of every month incredible.
The only story I didn't really like was Goyer's. I mean, I thought it was a good story and I enjoyed it, but it lacked punch that the other stories had. Life Support was a great story that I felt ended a little too abruptly, but I absolutely loved it. My favorite was the Donner script & storyboards "Only Human". It was a nice, fun little story that brought a smile to my face.