The Buddys are carberated, and they have a "redline" mark on the speedometer at 55mph. You don't want to cruise faster than 55, or you WILL blow up your engine. They're buzzy, only get 75mpg, and have teeny little wheels that make even the smallest grooves in the road or tiny potholes harrowing.
That said though, Buddys are good, solid bikes. My wife's has almost 14k miles on it and still runs like a bat out of hell. It's a blast to ride, much more flickable and nimble than my PCX or any other bike I've ridden. If you're stuck in the garage, just pick it up and turn it around (it's that light). There's a reason we've owned 3 Buddys, they're great scooters.
If you're going for economy first and foremost, look at the Buddy. You can't beat the low maintenance cost, cheap parts, and dirt-cheap initial costs. I like my PCX better because it's smoother and more well-built than the Buddy, but I'll NEVER recoup the $1000+ I would have saved from initial sticker cost through the better gas mileage my PCX gets. It's like driving a base-model Yaris vs driving a Camry. Both will get you there fine, and are mostly the same. But the Yaris on the highway shakes a bit, has less features, is smaller, and less comfortable. In this analogy though, the Camry gets better fuel economy.