Well, there is really no point in arguing with me about Marth vs. Sheik because my personal opinion is that Sheik is the best in the game. Better than Fox, Falco and Puff. Thats just me though.
Sheik has a hard time against:
Fox
Falco
Jigglypuff
Ice Climbers
Doc
Mario
Peach
To be specific, I'd generally say the match-ups are about (without specifying stages):
Fox 65:35 Sheik
Falco 50±5:50±5 Sheik
Jigglypuff 55:45 Sheik
Ice Climbers 65:35 Sheik (probably exaggerating)
Doc 50±5:50±5 Sheik
Mario 50:50 Sheik
Peach 55±5:45±5 Sheik (this uncertainty accounts for Sheik potentially being better, I don't think Peach would be better ever than 55)
I can explain all of these easily and in depth, but most people don't ask my opinions. Just ask specifics if you're curious, really.
Allen, I feel you're quite biased from playing against me. I would summarize that match-up at 60:40 in Sheik's favor, simply because a Falcon in control is a Falcon ahead. It's like Sheik versus Fox, whoever is in control has the major upperhand, but Sheik can stop Falcon's control more easily than Falcon can stop Sheik's, just as Fox can more easily stop Sheik's control than Sheik can stop Fox's (and his control is easier to maintain and initiate).
Jigglypuff is definitely not better than Fox or Falco. I wouldn't really say better than Sheik or Marth. She's just one of the trickiest match-ups in the game. Jiggs can be played
generally the same against almost all characters. However, as a character that isn't Jigglypuff or Peach, you have to treat her much more differently and take a much more wary approach. Too many people autopilot or they choke, and choking against Jigglypuff easily results in losing a stock due to her having of of the best two punishes in the game. Not to mention her bair is pretty ********, but I don't think she's really better than sheik or Marth, just no par with them and around them. Also, not being able to really gimp her in a traditional manner adds to how different she is.
I don't exactly remember the new tier list, but I firmly believe Fox and Falco are the best, with Fox being better. Falco has a variable recovery and can be tricky, but it's still a much more limited window than Fox's. Marth, currently, has massive under representation and is about on par with Sheik, I'm not sure and I don't care who is favored overall. Sheik has the favor over Marth, but Marth has the favor against almost all other characters that aren't low tiers except Falcon and Ganondorf. Ganondorf does much better against Sheik than people give him credit for.
Et Cetera.