Razor: Is He Effective?

I've been finding myself playing Razor a lot more recently whenever I see any sort of high damage hero on the other team, or a hero that builds almost pure damage (think carry prophet, kunkka, etc.) and have been wondering about why everyone says he's not "relative" to the meta.

Sure, not a pick you'd take just because of what he can do, but I think he can be used to stop what the enemy can do. Think a Phantom Assassin that has no damage, those crits aren't going to make a big difference. While we don't see hard carries picked that often, I think he still works, especially when you can counter others.

About the build: Why does everyone say he need vanguard? Last time I checked vanguard is a pretty bad item for the cost, since Razor shines in the early/early-mid game and the late-game, why doesn't he build early items? A core of Treads(or PB depending on the speed of the other team), Drum, Mek, Wand, Vit Booster (later into heart) seems like it work would wonders and is probably feasible in the first 20 minutes depending on if you did well and got some kills early on.

Why isn't he picked up more often?