I have not noticed any behavior differences, either, but none of them have any behavior problems to speak of. Just occasionally a little lazy and self-centered and whiny when they have to do something they don't want to do!
What we have noticed is a lot less hunger from 3 out 4 of them. But the youngest, Davy, has been eating like he has a hollow leg. It is astounding. DH measured them only a couple of weeks ago. We just checked and he has grown 3/8 in. in three weeks! So that is why he is eating like a small horse! I'm glad he is getting fat and protein for this growth spurt.
The other three have been quite satisfied between meals. It is nice to have less people milling around opening cupboards and refrigerator doors and asking for food!

Kristi