I flew one of these back in December. I was connecting at IAH headed to EWR and was scheduled to leave on a later flight but once I arrived at IAH, I saw this one was delayed, so I went and asked if I could get on it - I got a boarding pass right away - when I entered, there was at most 1 person per row per side - I was assigned an exit row seat until the gate agent came in few minutes later and gave me a boarding pass to sit up front in the BusinessFirst cabin. It was my first time traveling in BF and I kept thinking why they are sending it out so empty but once I got to EWR, I found out it was continuing on to LHR, so obviously they needed it back at EWR to continue to Europe.

On another note, I have had a lot of changes for flights booked in June and often I've had a new aircraft substituted - mostly 757s replacing 737s on transcons. Very nice.