I have noticed two things with Overture.
1. If you have $500+ in your account your reviews will
go through A LOT faster. Mine are usually done in 48
hours tops.
2. You are likely to get approved for most of the keywords
you submit.
I've noticed this on two overture accounts I have had over
the past few months. I keep on charged up in the $500+
range while the other is in the $70 range.
The $500 always goes through a lot faster on support,
reviews and approvals.
Luc L.