We are using YSlow application and Fire Fox 6
Talking about the comparison of template of those companies:

• YOOtheme with Revista
• Rockettheme with Clarion
• Shape5 with Cyan
• YouJoomla with YouRetro
• Gavick with eSport
• JoomlaXTC with Barista

BusinessClass is a clean, fast-loading, SEO-friendly,Business styled Joomla Template for multi application use. From Travelsites and Appsites, to Hosting Companies and Green Friendly projects ,or just about any business venture, BusinessClass has your style covered.