There are a lot of discussions on why Apple changed the new MagSafe power adapter. First of all they made the new one thinner and therefore incompatible with the "old" MagSafe. The reason for this, Apple told us, was that the new models become thinner and thinner and at one point the MagSafe adapter would be to thick for the new MacBook body. This is kind of sad because until know you could charge every mobile Intel Mac with the same adapter. But at some point you have to change even the most popular connector (we will most likely see the iPhones/iPods/iPads Dock Connector change) So even if we are not yet at the point where it really had to change, I am ok with that.
The other thing that changed is the form of the connector from an L form to the T form which it had at the beginning if it‘s life. There are a lot of complaints about this too. Most of them saying that the the L form is much better. I think this isn‘t that easy to say. Since pictures can say more than words and I am not that good at writing words I made a video:
The purpose is to state two points. First of all, not all MagSafe 2 magnets are too weak. Mine is more on the too strong side. Second, even if the L shaped connector has a much weaker magnet, if pulled from the wrong direction it is extremely hard to pull of.
Correction:
I wrote MacSafe but the connector is acually called MagSafe.
When upgrading my MacBook Air to Mountain Lion I ran in to a problem, which drove me nuts for a few hours. After I started the install process of Mountain Lion the MacBook Air rebooted and presented me, as expected with a password screen for my File Vault 2 encrypted SSD. Since this is my first machine with an encrypted boot drive I already feared trouble with the encryption and I did not have to wait very long. I entered my password, which only caused the password field to shake as if it was rotten. My password is very long and it‘s not unusual I get it wrong the first time. After the fifth attempt I was convinced there was something wrong.
I rebooted the Air hoping it would boot back into Lion, which I did not. Even pressing the option key wouldn‘t help it. I thought it was broken but hesitated to enter the recovery key or go back to the backup I made with Carbon Copy Cloner.
Since the Air is only my second machine I set it aside and ignored the problem for a while. When I booted it up some hours later, my password still did not work but, much calmer now then befor, I discovered a small keyboard layout selection field in the top right corner. I switched over to a German keyboard layout and everything was fine again. (I‘m sorry that I have no picture of the screen)
Lessons learned. Apple isn‘t as perfect as I would love it to be. Passwords with special characters are tricky. Nothing new here but sometimes you have to experience it on your own.