Re: Difference between F4 and F5 other then looks
While it's not a complete analogy, think of the difference between the sound of a carved-top, f-hole "jazz" guitar, and a round-hole steel-string. The round-hole guitar is (most likely) a flat-top rather than a carved-top, so not strictly analogous to a carved-top, oval-hole mandolin like an F-4, but you derive some of the acoustic differences.
And you could build an oval-hole, 14-fret-to-the-body, raised fingerboard mandolin, should you want to. When Gibson "reissued" the F-4 recently, they made it with a longer neck and raised fingerboard. One in the classifieds now.
Gibsn: '54 F5 3pt F2 A-N Custm K1 m'cello
Natl Triolian Dobro mando
Victoria b-back Merrill alumnm b-back
Stradolin Vega banjolin
Sobell'dola Washburn b-back'dola
Eastmn: 615'dola 805 m'cello
Flatiron 3K OM