IMO, Vintage is more about deckbuilding and aiming at running on autopilot than it is about player skill. All most decks do is find an engine and then push it as fast as possible and try to ignore the opponent.
Which is the right strategy, but it doesn't make for in-game skills like Limited does.
Following Az's example, I couldn't agree more with what JP added.
if you can't see the effect of not maximizing the effects of your cards, it's harder to improve your skill. It's a lot easier to see this if you play a lot of Limited, because it's harder to set up
The last time I played T2 seriously was during Invasion block and after two sabbathical blocks. I realized I was getting rusty with so much magic theory that I decided to blow off the dust and attend the Mirrodin prerelease. I didn't even cared to read the spoliers, just wanted to see how well my playing skills standed at that point.
I had never before attended an event here at Mexico City before, so I faced a completely random environment in that sense. After reviewing the cards I received, I built a R/G beatdown deck with enough artifact hate and finished unbeated in the top 8. I relized I was facing good players starting the second round, so I played carefully, holding always some burn or artifact hate available, and never overestimating my opponent.
Since you never know what to expect from your opponents at limited, and the card pools are more restricted, you get used to find solutions with what you have available, innovate and find alternatives during gameplay. This is why I consider that Vintage players that both play limited and
seriously construct budget decks have an edge in
overall skill over the other players.
edits in bold