We are the live people or animal. Everyone do everything always has bias, right?
For dual agent, it always 60% towards seller's interest and 40% towards to buyer because agent know / meet seller first. Agent get first impression already.
But if you are experienced buyer and keep this in mind (OK, I know you will work more for the seller. I don't care), then it is OK.
Why you are "planning to buy rentals starting from 2010"?
Today, U.S or whole world is in market economic, market is wild. You have no way to control it. How can you PLAN it?
Don't wait! Start it tonight. Anyway, 2010 is 4 months ahead you.