Valor gets shield proficiency, which is pretty significant since medium armor alone may not improve your survivability at all. A valor bard can get to AC 19 pretty easily with only moderate Dex, so a Str Valor bard is viable. Battle magic lets you cast Green Flame Blade or any other smiting attack you've stolen from Paladins and still get a bonus attack for potentially 3d8 + Str/Dex + 2d8 + Cha + 1d8 + Str/Dex, but that's basically an endgame ability and I don't believe it should carry much weight in consideration. Valor also lets you use bows; it's not limited to melee weapons.
Sword's Blade Flourish is very good, mainly because it grants +10 walking movement and doesn't cost an action to burn a die, but it doesn't combine with any SCAG cantrips. Fighting Style is very good, too. Sword's bonus proficiencies allow the use of weapons as a spellcasting focus, if your play group actually cares about that sort of thing. Flourish Master is truly absurd, but, again, it comes at level 14 which is basically endgame. You shouldn't judge classes based on abilities at this level unless your campaigns are restricted to high level play.
Sword focuses on making your swordsmanship better. Valor focuses on making your ability to fight better in general.
Both classes can make good use of the Shillelagh cantrip, of course.
