Not a good comparison, I have to point out. You appear to have had one VPS on each service and run the test once on each. No idea how old either was, how crow

Not a good comparison, I have to point out. You appear to have had one VPS on each service and run the test once on each. No idea how old either was, how crowded the host you wound up on was, or any of that. So interesting, but not scientific. For all I can tell, the Slicehost VPS may have been very old, and the Linode VPS may have been brand new on a fresh machine (so no one else was using it and eating into the disk access times). The forums for both companies have customers talking about hdparm results and such, so it's worth looking there for a broader sample. In general, people testing an existing VPS against a new one (for either service) tend to see better results on the new one. It's just a fact of life if you get a VPS - the old hardware stays in service because customers still run on it, and those customers don't want unnecessary downtime. For best results, make a new slice on each, talk to the techs at each to make sure you're in their latest and greatest datacenter, and then see how things stack up. It's also worth pointing out another caveat with a VPS - shared disk access. So for scientific results you'd also need a way to control for the number of users on the box, and their usage patterns. If some jerk on your machine consistently thrashes the disk with swap access, it's going to be a pain on any service until their admins see it happening and reboot that VPS.