First of all, thank you for your note. I think it's particularly valuable for pilots and controllers to have an open dialogue and effective communication. From my 25+ years of flying the line, I honestly believe that ATC personnel do an outstanding job of moving traffic safely and efficiently. Having been based at ORD for a number of years, I'm partial to those men and women who keep the flow moving through the windy city but that doesn't detract from all the rest of you guys and gals who are equally as proficient. If I may, for the younger pilots on the forum, if you get the chance to visit the tower or a TRACON on a layover or a "field sit", do so! From my experiences, it's time well spent and if a controller wants to jumpseat on your aircraft, welcome them onboard. It will pay huge dividends downstream. Even though 9/11 has changes some of the requirements for a facitity visit, make the effort to do so. You won't regret it and it will broaden your horizons immeasurably.

Ksatflyer; your questions have been answered. The preferential runway request most likely are because of obstacle clearance and second segment climb requirements and not runway slope. As has been stated earlier, they can be significant depending on surrounding terrain.

Let's keep a dialogue going between pilot-controllers. It's well worth while and thanks !!

G'Day Mates