X-E1: Viewfinder is horrible and kit zoom is heavy, but then ...

1) The build quality is very good, the camera body is just light. I agree that it felt cheap when it came out of the box, but once a battery and lens are added it feels very nice. You will appreciate that lightness when you have been carrying it with you all day. Sure beats lugging around my 5D MkII and lens...

2) I haven't held the zoom, but I would assume that it would throw the balance off. That is the price we pay for wanting a light camera and a fast zoom lens. You can't have it all.

3) I think the EVF is great... for an EVF. Coming from the full-frame 5D's pentaprism viewfinder, it is different, better in some ways and worse in others. There is still room for improvement as far as resolution and refresh rate goes, but none of this should be a practical hindrance. It is far easier to manually focus using the EVF's zoom feature than it is on my 5D.

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Fuji X-E1 w/ 35mm f/1.4 and 18mm f/2.0
Canon 5D MkII w/ 24-70 f/2.8, Sigma 50 f/1.4, Canon 85 f/1.8, etc, etc...