Bandboy,

This is a slightly difficult question to answer as everyone's needs are different. It is up to you to determine which aspects are important and then select your colocation provider accordingly. With that said, there are some standard items that most companies look for.

-Redundancy - Not only from a network perspective, but are the power and HVAC systems in an N+1 configuration

-Security - Man Traps? 24/7 on site staffing? Video cameras?

-Access - Does the facility offer 24/7 access to the rack or do you have to pay for escorted access?

-Power - What is their current load on the UPS? How much power do they have left. A datacenter is more likely to run out of power than physical space

-Support - When there is a problem, do you get a live person when you call?

There are many more categories and I could go on for hours as this is what I do all day, but for the most part, these are the top 5 items most groups look for.