Case:
I selected a site that I have had in production for some time, but recently upgraded to Drupal 7 & Commerce Kickstart 2.4. The problem was that some of the heavier coded sections of the site would take minutes to load. The front page could take 3-6 seconds to load, and other user pages could take as long or longer. This is a low traffic site.
Task:
Test the site on different platforms.
Method:
I created a new hosting account with my current host provider to give them a fair shot.
I setup nearly identical Ubuntu Virtual Machines on two hosting providers, Amazon and another.
I installed this site on all three servers.
I used pingdom.com and gomez.com to test. I went with Pingdom as my primary tester as I could setup interval testing around the clock.
Pingdom reported Amazon response speeds averaging 100ms better than the identical Ubuntu server and 1400ms better than my original hosting provider.
Conclusion:
Using Amazon, Front page response times were cut to sub-second responses. Heavily coded pages load in seconds vice minutes.
Even hosting four low traffic Drupal sites, Pingdom is reporting 300-500ms front page responce times when testing all sites at a five minute interval.