http://serverbear.com/9683/linode#view-uptime-beta
Plus benchmarks etc (user run, which means you get a decent dataset to compare by server spec/location).
http://serverbear.com/9683/linode#view-benchmarks http://serverbear.com/9806/digitalocean#view-benchmarks
We've actually considered ticket response times, a lot of hosts use WHMCS to manage their nodes - which we could make a plugin for. But a large amount of the more established hosts use a custom system.
Problem is, ticket response time isn't an indication of quality. Anyone could respond with a "We're looking into it" within 5 mins & not get a resolution for a few hours.