What are your criteria when you are about to choose a colocation service provider? What is more important - data center tier, location, connectivity, cost of the remote hands, management services, or anything else?
All of the above, but I'd also query if they had multiple backup generators (and if they are routinely maintained and tested), if they had battery backups, how the servers are cooled (cold row containment or what), plus others.
From my experience, customers look at pricing, connectivity and backup features for power.
Timely responsive remote hands also make a DC very attractive. In the end, when something goes down, you can not be running to the DC each and every time. Remote Hands is crucial for this (and it needs to be cost-effective too).
Nobody has mentioned the geographic location of the data centre.
Partially, with regard to data protection and privacy laws which could also be a factor depending on what it is that you are planning to be hosting there, but also susceptibility to national or regional power outages and natural disasters.