I was at the arcade a couple of times over the weekend and can confirm some of the changes made.
I took a very short, very shaky video of Daioujou. You can see that the monitor "blue" issue has been fixed and that the difficulty has been taken back down to normal:
http://www.youtube.com/watch?v=WuN_C4s-jPI
And I updated my "community" record of Donpachi on the new "normal" settings. I can confirm that it is not US, it is definitely another version, probably japanese, as Zerst has said. In any case, I played one game on Saturday and got to 1-5 with 7.1 million, and on Sunday I played one game as well and got a new high score of 8.3 million, reaching the final boss of the first loop for the first time.

Now that the machines have been restored to normal settings, we're hoping some members of this community can stop in and set new high scores for us to strive for.
I hope to see all of you at the arcade sometime soon. Thanks again for your feedback.