I am about to book a business class trip from Dulles to Heathrow and it appears that the alternatives are Virgin, United and BA. From the Virgin site, it appears that the new suites have not yet been installed on the Dulles flights. I cannot determine the status of the BA upgrades or the Untied upgrades.

My principal miles are on American, so mileage is not relevant to me. Which airline will offer the best overall business class experience?