Magsafe is crap, the cables look ugly and break in no time. They're also no faster to connect than say HP or Dell round power connectors.
Round power connectors are crap. The jacks stretch and stop making proper contact in no time. Apple used to use them back in the PowerBook days, and on the PB 145, I broke at least three cables and at least two or three jacks on the back of the device over the course of three or four years.
Magsafe connectors are a godsend by comparison. In the eight years or so that I've been using them, I've broken zero ports. And if you don't count the recycled MacBook Air cables that I was using with my rechargeable external power brick, I've also broken zero cables. (If you count those, I've broken two or three, but given that the external power brick company cut them off of dead power supplies, odds are good that they had been seriously abused long before I got them.)
Magsafe 2, however, is a train wreck. The contact surface is too small to have any real grip, so they tend to fall off while I'm moving my laptop from a tray table to my lap. That "upgrade" was a huge step backwards. That's the one thing I really miss about the pre-retina MacBook Pro, and I'd be more than happy to see Apple add an extra millimeter of thickness at the edge of their case (the center is plenty thick enough) to allow them to go back to the (far superior) earlier design. With that said, I did appreciate the lighter weight of the Retina MBP when one fell edge-first out of an overhead bin onto my head a few months ago... but I digress.
The new USB power connector is doubly bad, because it has all the same problems as the older, breakage-prone designs, plus it steals your ability to use your USB port without plugging in a clumsy adapter cable. The absolute last thing I want to do is have to carry around some weird splitter cable just so I can charge my laptop and a cell phone at the same time. And of course, as an iOS developer, I keep more than one cell phone connected to my laptop for much of the day, so the new MacBook really would be nightmarish from my perspective; I'm hopeful that Apple does not even *think* about taking their Pro line in that direction.