What do you use interdomain routing for?

HI, We are looking at requirements for interdomain routing, and are interested to know what you use it for. For instance, do you use interdomain routing to select transit carriers for some traffic in preference to other carriers. Are there policies that you would like to be able to implement that you are unable to because of limitations in the available protocols? How much would you be willing to slow down your forwarding rates in order to have the capability? Please send me your answers and I'll summarize. --Neal