Switching over from Canon DSLR system to compact ILC system?

[howieh]

Hello,

I currently own a Canon 550D with a couple of L lenses (17-40 and 24-70). The problem is I am really bothered by the weight and size of the DSLR system (especially the size and weight of the 24-70) and have recently looked into compact ILCs as alternatives. I am not a professional photographer (obviously), but photography is one of my main hobbies and I do travel a lot.

With my current budget, I can afford a NEX-5n plus the digital viewfinder (or, if necessary, shell out $300 extra and get the NEX-7), and then I plan on getting a Sigma 19mm F/2.8 and Contax Zeiss 50mm F/1.7 (with adapter). I might get the Contax Zeiss 90mm F/2.8 as well if it turns out I really need it.

Some concerns I have:

1. First and foremost, I care about image quality the most. Does the aforementioned NEX build match with the Canon build in terms of image quality? (low light performance, colour, sharpness, etc.)

2. The other thing is, I have never been a serious prime lens user (I have the cheap-but-capable Canon 50mm F/1.8 but rarely use it), so the prospect of switching over from zoom lenses to prime lenses is also a concern. With zoom lenses, I don't have to carry all my lenses with me; right now, with my Canon system, most of the time I use my 24-70 and it does the trick for most situations.

3. If I am getting the NEX system, then I most likely have to sell my Canon system to free up enough cash.

4. Any other suggestions/advice are also much appreciated.

Do you guys think if I should make a switch?

Thanks to you all in advance!