I would add that one should also compare cancellation and prepayment policies for the convention/conference room block versus conditions for whatever other rates rare available. Often I see conference rates requiring payment at the time that the reservation is made with a cancellation penalty of two nights' charges and even the full amount if cancelled within seven days of arrival for normal city hotels.

I've also experienced situations where the host organization tells the hotel who to upgrade (meeting planners, officers, board members, session chairs, etc.--a certain number of upgrades might be required by the contract) from the room block, but if the reservation is made independently, the elite is much more likely to be upgraded.