I think I'm still pretty good at the IC matchup. I don't know if I would've beaten him or not, but I would've gone into the matches with a lot of confidence. The matchup is so straight forward, I can probably put it into M2K terms. (Wobbles has beaten my Marth before, but I did win pretty consistently against him.)
Marth vs. ICs is one of my best matchups even if I haven't played it in a while, I think I still have it figured out.
Looking at the matchup objectively, I'd rate it as one of ICs worst high tiered matchups next to Fox and Peach. Nowadays, it's probably a bit closer with ledge chain throws into wobbling and nastier edgeguards, but I'd still put it at a 60-40 Marth at least.
It's one of the few matchups where everyone's perceptions of Marth are actually applicable. You can even use Mow strats against them with great effectiveness. It's just harder for them to slip the cracks than other characters. Not to say it's not impossible, Wobbles and Fly are easily the scariest ICs for any Marth to fight, but it's REALLY hard to slip in on Marth, and it's soooo easy to mix up your swings. You can literally just swing your damn sword around, it's the ONLY match-up that I can think of where that's legitimately effective in the current metagame.
Wobbles is hopefully moving in with me next week, so all of this is subject to change.