Carrier Selection

As we have been extending our private peering relationships across the US and Europe we are also looking to consolidate our carriers to simply Tier 1 and/or near Tier 1 providers. One of these providers will certainly be Level(3), but we are still not fully decided on other carriers.

Now, what I am looking for here is, which network combination would most impress you as a customer/potential customer. I am not looking for price based analysis or analysis of dealing with a company's billing or support departments. I already have the data I need for those determinations. The point of this poll is solely to get end-user input as to overall network performance/reliability and how the network would compliment the existing carrier, Level(3). Please elaborate as to your decision in a post to the thread.

Note: We have already done significant research, this poll is simply to help confirm research we have already done or to bring about items/issues we may have overlooked or not considered. Figured we'd take advantage of the knowledge of this community before making a final decision.