I've had a ton of problems with the TB2/miniDP port. I still use it for my display connection and GigE to both a 15" and 13" MBP, but it can be intermittent and flakey.
Oh yeah, I agree with you there. I do have a few Lightning cables that have died, but I treat them as consumables anyway.
I know it supports some form of USB3, but the display out is handled by having a h264 decoding dongle (!). It unfortunately doesn't have enough pins to really support the range of alternate modes and high data speeds of USB3.
It looks to be a much simpler and sturdier connector.