Both characters are fast - Sonic moves and chases much faster than Fox- at least, sideways and upwards. Fox definitely falls faster, which lets him chase downwards and shine people to death under the stage, but otherwise doesn't have alot of value aside from escaping juggles, IMO
both characters are very light - Fox has faster fall speed and is lighter than Sonic, who is heavier than Marth. Hope that made sense lol.
but Fox does more damage - per move, yes.
has more knockback - correct
has better aerials - Fox's aerials have alot of commitment (like, his F-air, N-air, etc all stay out a really long time, unless you land).
has a projectile - correct
a reflector - correct, and it's very useful.
can recover as well as Sonic.- ...not really. Sonic has more options in his recovery with wall jumps, homing attack, spring, side-B extra hop+double jump, FSJ after spring, etc. Fox is limited to long distances horizontally and cannot piggy back on other peoples' recoveries. This is the only one that I find horribly wrong.
To add:
Fox's smashes come out much faster than Sonic's (+ for Fox, since it makes killing much easier)
Pretty much, what Sonic has over Fox is:
+ weight
+ cancellability in approaches
+ grab/chasing game
+ off-stage game
+ disrupting projectile (spring)
+ less-gimpable/more versatile recovery
I'm not really sure if Fox can jablock, but Sonic can. Sonic has aerial combos that are generally for damage, whereas Fox has grounded combos (which... kill)