Help needed - Upgrade or Downgrade?

Hi,

I am a hobbyist but I have used a 5D2 with a couple of L lens for about 2.5 years now.

I am considering moving to mirrorless but am not sure if the move will be a right one. I need some advise, especially from someone who has both a FF DSLR and a mirrorless camera experience.

The main purpose I used my 5D2 are for family gathering, festive seasons, friends' wedding (non-professional), travels, landscape. I do not make money from my photos. The photos are mainly for personal viewing only.

My thoughts of moving to mirrorless, more specifically the Sony NEX 6 is because I find the 5D2 under utilized. It's heavy and bulky to be carried around. Even if I go on a local holiday by car, I would feel reluctant to carry the DSLR with me because I just want to enjoy 'the holiday.' However, my family love the shots from 5D2, so my wife is considering us upgrading to the 5D3.

The upgrade to 5D3 is the easy path where I can sell my 5D2, top up some cash and get the 5D3. I can re-use my L lens, speedlite, extender and Lowepro camera bag. But I am still stuck with the whole weight problem.

The downgrade to NEX 6 is the path to the unknown because I am not sure of the quality from a mirrorless camera. I also have to sell all my 5D2 and lens because I am moving to a different system.

I am quite cling to the thought that a smaller camera will do more justice for my kind of use. Appreciate any advise given and if the topic bothers you, please refrain from responding.

Thank you, really.