I have a few F3/7s. Post War and modern Santa Fe, K-Line NYC, K-Line and Williams Texas Special, Williams Canadian Pacific. I especially like the K-Lines. Both A units powered and choice of three pilots included.
I love E's and F's. My most memorable cab ride was in the cab of a F7 through the Royal Gorge in Colorado. Currently I have 4 ABBA sets of F units. 2 MTH premier Santa Fe sets in warbonnet, 1 MTH premier SP black widow set, and 1 Lionel Legacy Rio Grande set. Sometimes I'll have an operating session with just F units.