We just got back, suffering from the post-Disney blues!
Weather was great, mostly in the 70's, we had just one day in the 80's. MK was supercrowded the night of 3/4, but it was open late so that is probably why. No problem when we went again on Wednesday. The crowds were light, we were using fastpass in conjunction with waiting in short lines - rode Soaring and TestTrack 9 times total

, waiting for 20 min only once! Same with BTMR - my son fell in love with that so we rode it about 4 times early

, just needing fast pass once, and standing in line for 20 min later in the afternoon.
I noticed alot of the stand-by boards would say a 20 min wait, but it never seemed that long.
It was in the 80's when we left Sat, back in the 70's now. Don't know how the crowds will be on the 17th. They may pick up with spring break, but never been there then.