We operate all of our datacenters in a multi-master configuration across the WAN, so latency is something we need to be mindful of. We were also in the middle of an emergency situation that required a migration, so we needed a solution that would allow us to evacuate quickly.
In the end we decided that we wanted a provider who supported a VPC-like network configuration, and was roughly within the same latency profile as Linode in respect to US-WEST-1 and US-WEST-2.
If timing hadn't been a concern, we may have chosen differently. We felt we didn't have the luxury of time.
Bah. More virt. Throw down some cash on a cage and fire up AWS Direct Connect, man. It's bliss, you get more choices out here than I did with us-east-1, plus you guys can afford it now.
We plopped in physical gear for a couple parts of our AWS infra a few employers ago and cut our Amazon opex by like, two thirds. Not helpful for your using Azure as a reliability strategy, but worth thinking about for your write-heavy databases, for example.
I have been doing some research in my (limited) spare time to try to find a new provider, but I still have not made the switch from Linode.