This is my impression of Link post patch.
http://smashboards.com/threads/1-1-3-patch-notes.425921/
The bad:
Dair getting a ground only hitbox takes away some combos like Bomb thrown down>footstool>Dair lock>Fsmash.
The good: Link got significant buffs to one area he needed them: killing.
His up launching Dsmash1 now hits at a steeper angle and harder. Fsmash 2 also hits slightly harder. These aren't huge but Link gets better reward on hit.
UpB links hits better. Consider the implications with Link's Dthrow; he has one more option to chase opponents in the air and possibly kill. IDK how escapable it is but I have had much better success landing every hit. This also buffs Link's intercepting game; he can SH Dair/Fair/Nair offstage then upB to the ledge (or past it) for a significant wall of pain offstage.
Fair got massive power buffs. The damage for both hits is improved and the BKB for hit 1 is doubled. Bomb>Fair 1 kills almost as early as Toon Link's (both hit frame 14 btw). Killing at a lower % means Fair is easier to chain from bombs/Dthrow/Dtilt because the opponent is launched closer. Considering how safe Fair is (good shield stun, range, cuts 2 times to catch dodges, 12 frames landing lag) this is significant.
Consider these when thinking buffs on characters like Mewtwo will switch the Link MU in their favor. IMO Link is planted in mid-tier instead of hanging on the lower edge of it. Link still has terrible MUs with relevant top tiers like Sheik, ZSS and Fox. His slow frame data and mobility are the same. But he has better, more reliable chains and killing options for every MU now. It's sort of like saying 'instead of a -1, Link now has a -0.5 MU'. Not enough to drastically sway anything but nice all around.