I used the Silver Line to IAD got the first time on Thursday morning. I live in Vienna, so need to take the Orange Line to East Falls Church first. I had not thought to check the schedule, so arrived at EFC after taking the first train early in the morning only to see a 45 minute wait for the Silver Line. That is, the first train doesn't leave EFC until 5:52 a.m.

Fortunately, I had the time. And I should have thought to look at the schedule. It took about 40 minutes to IAD, by the way, so I am skeptical of claims of 45 minutes from Rosslyn.

Also, note that there is summer track work approaching and the early part of it (starting June 3rd) will have the stretch of the Silver Line from McLean to Ballston closed, presumably with a bus bridge.