I find the commentaries on the DVDs by JL Dreyfus, M Richards and J Alexander quite boring. If these are what they got extra paid for, then it is a huge waste of money.
For long periods of time, they don't say anything. It is also not very interesting to hear 3 persons laughing for 20 seconds in a commentary. And when they say something, it's like "I haven't seen this since it was originally aired"...
There is no interesting background info as there is when Jerry Seinfeld or Larry David comments.