I'm gonna list my opinions of the buffs that characters received in this patch, and see how it could affect them...
(I'm only going into the confirmed changes as of this post. Characters like Falcon and Charizard are supposed to have changes, but haven't been found yet).
: Well then... The Up Throw nerf could affect him, though not by much. Basically all it means is that Bowser has a very tight window for the Up Throw Up Air combo now. Before, he could miss three or so times and it would still work. Now, it appears that it only works on the first time. Miss that, and you can't do it. Shouldn't really effect him at top level play. Dash attack doing 2% more is welcomed though. It will be slightly safer, and will kill slightly earlier (not that it is/was the best killing option, but another option is another option). Overall, I see no change.
: The endlag reductions on his smashes are very welocmed. They aren't game changing like Bowser's Up Throw in 1.1.3 was, but it makes his laggy finishers less laggy. This potentially makes Down Smash go from useless, to usable. The increase in damage on Forward Air is also welcomed. It won't stale as much, and it's one of his better aerials too. Overall, could push him up a space or two.
: Falco got a few sweet changes. Again, not game changing, but useful. Up Smash comes out a frame sooner, and in doing so hits smaller/mini/crouching opponents, AND deals increased knockback. Recently discovered by another user and confirmed by me, his Down Smash also kills earlier (albeit, only 5% earlier uncharged). These give Falco more reliable killing options outside of his Fsmash. Like I said, not game changing, but could push him up a place.
: A negligible change. Weight buffed from 112 to 113. Still, a buff is a buff, though not enough to move him on a tier list.
: Two small, but useful changes. Fair and Nair each deal 1% more damage. Seeing as these are two of his most useful moves, I could see him going up a place or two in the tier list.
: Kirby's weight change is more relavant than Ganondorf's, because he is super light, and it's more than 1 unit change. He went from 77 to 79, but it won't move him up in the tier list. It is a very helpful buff though.
: I'll be honest, I could see Little Mac either staying the same, or dropping a place or two after his changes. So all of his smashes deal 1% damage. This means they could kill slightly earlier. This is nice, but he didn't need that, especially when they killed early anyway. But what makes me think could harm him most are the angle changes he received. Up and Down Throws going from 85° to 80° is most likely a nerf, as opponents will be able to DI away easier, escaping potential follow ups (such as an Up B). The most harmful change though is Dsmash's launch angle going from 30° to 45°. Him attempting to edgeguard with the move will be far less effective, as the move no longer semi spikes. Even the increase in damage won't help. All in all, I see him staying the same at least, but I could see him dropping.
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: Here is where the buffs start getting interesting. The buffs these pair received are game changing for them. Most notably, the damage increases help them out the most, Marth especially. Not only does it help stop their moves getting so stale, but it helps with their lukewarm damage racking game. More importantly, it helps improve their combo and juggle games, not just because of them dealing more potential damage, but the higher damage on the moves helps them put opponents into hitstun for longer, allowing them to combo and juggle for longer. This is especially noticable for Marth, as his sourspots deal reduced knockback anyway, meaning that, he can now combo with them for longer. Utilt and Ftilt are quicker, with Utilt being able to combo into itself easier/extend falling Uair combos more reliably, and for Marth, the quicker Ftilt buff grants him a relatively safe kill move (tipped), similar to Roy's Ftilt. Dsmash is 10 frames less laggy, being now much less laggier than Roy's (though it's still a relatively niche move unless tipped) is welcomed. Some of their moves also even have slightly increased range, with Fair and Dtilt being the most notable ones, Fair becoming even more useful, and Dtilt (more so for Marth) being able to hit opponents recovering to the ledge easier thanks to increased sweetspot size, and gimp them. There are even more changes being discussed/discovered over on the Marth boards right now! Overall, I can see both characters risng a fair few spaces on the tier list. Marth is certainly at least on par with Roy now, no question.
: 78 to 77 weight change. Negligible really. In reality, she will get killed 1%/2% earlier, but will potentially be able to escape a hit of a combo she couldn't before (such as an Up Air from Falcon, and Up Tilt/Up Air from Mario etc) Not a change enough to move her on the tier list.
: Roy's changes are welcomed... BUT, in my opinion, they still don't change him that much. He still has no safe approach option. The landing lag changes just make his heavily unsafe approach options, just unsafe. He still has no effective aeiral defensive walling game like Marth has for example, and the landing lag changes don't really help him in terms of extending his combo game. He could rise a space or two, but not much.
: NERF SHEIK, NO LONGER TOP TIER... unfortunately not. The nerfs aren't severe enough I don't think to effect her viability. Still the best character in the game. She will just die earlier, and one of her best killing options (Dthrow to Vanish) will kill 4ish% later, and also have a slightly stricter hitbox. Other than that, unchanged.
: 95 to 94 weight. Almost negligible. He will die 1-2% earlier, but it honestly doesn't affect him at all. No change.
: Well these came out of nowhere. Not that he needed any buffs, the buffs he got were appreciated. Seeing as Bair is one of his best killing options, having 4 less frames of landing lag is nice. And the startup of the hitboxes on Spin Attack are generally useless, but a buff is a buff. I doubt he will rise because of the buffs, but I can see him rising anyway due to his recent performances.
: Weight from 81 to 80. Again, similar to Sheik. She will die 1-2% earlier, but it isn't enough to affect her viability. Unchanged.