I am flying PEK-IAD in F on Tuesday (April Fools Day) and I will also do a report here and post photos.
I went to T3 for the first time today to drop my wife and kids off (We spent the kids' spring break in PEK). T3 definitely reminds me so much of HKG. I have heard the long walk and slow train ride, etc.
I am looking forward to use it in 48 hours.