Soundfonts are easy to find and there is a ton of them around. Big ones, small ones, free fonts and paid fonts.
I decided to make a YT video to compare them using a MIDI file from Band in a Box.
(Communicating with Synthfont from BIAB is glitchy, even when using Loop.be or Springbeats or the likes, so I preferred a MIDI file. Loopbe and Kontakt works fine, no problems there.)
I didn't pay attention to the ability to play pop, rock of country. Only Jazz and the ability to make acoustic instruments sound good.
Njoy
BTW: If you view it on Youtube, you can easily find the snippets in the description, you can go from soundfont to soundfont if you like, using timestamps.
BTW2: Spoiler alert: imo, soundfonts are no match for Kontakt Libraries or even todays' cheaper keyboards (Korg Kross, Yamaha PSR)


Biab, Kontakt, Sampletank and lots of nice libraries, from Fluffy audio to Abbey Road drums.
Check out these great contemporary Jazz Styles: www.jazzstylezz.com