Is there any bitrate viewer/analyzer for aac?
I'm looking for one to figure out the actual maximum bitrate of VBR-encoded aac files.
I don't think I can go through hundreds of files, looking at the bitrate changes on foobar manually.
Any ideas to make this a little easier?

dbPowerAmp converter comes with a tool. You can try the 30 day free trial. The ripper and converter will stop working unless you pay. The tool will continue to work. That will allow you to read the all the tag info. The encoders record a great deal of useful info in the tag data which is not normally visable.

After saying that. I avoid AAC like the plague so I am not current. I am familiar with lossless and a variable quality of a fixed bit rate. I have never figured out a clean way to convert AAC variable quality to a fixed quality format. They are really apples and oranges. No matter how you try you can't get the square peg into the round hole unless you use a bigger hole or clip off the corners. That is a good analogy because there must be some serious fudging to get it to fit. I have given up the ghost.