That's awesome that you took the time to go back and find this 5 year old thread and update it.
I came across it while reading some of my old posts.
I don't think you should sell the XZ-1. Even when you DO find a lens good enough to match the XZ-1's, you'll find that the rig is not nearly as portable.
Unfortunately I have to downsize and one camera has to go (and I don't want to get rid of the MILC and large sensor camera). With an f2.8 lens the 12MP M4/3 camera should be adequate in low light(ish) situations. I am aware that it would not be a full replacement for the XZ-1 (or even the G2+12-50 mm), but I have to sacrifice something. The Sigma 19 mm is smaller and lighter than the 12-50 mm and I can use the change/difference in value. It also is a bit sharper and faster and I have always wanted to shoot a prime. Besides, even when I bought the XZ-1 in the first place I was compromising: I had had superzooms before and planned on buying another one to complement the XZ-1 but that never ended up happening. I have never regretted sacrificing the tele range for IQ.
Panasonic 12-60 f/3.5-5.6
Oly 17/1.8
I would definitely like to own these but unfortunately I can only dream of them for now...
The 14-42 pancake motor zoom is the kit lens that comes with a lot of the Olympus MFT bodies
This is a very interesting lens. Unfortunately according to two professional reviews it is less sharp than 12-50 mm and it is also more expensive at KEH than the Sigma. Hopefully in the future I will be able to expand my lens collection beyond the 34-38 mm prime. A 35-100 mm or Sigma 60 mm would be nice. Maybe an old MF 200 or 300 mm as well.
I have enjoyed my XZ-1 and my photo library has been greatly enriched by it, but I think it is time for us to part ways... I have decided to try to sell it here first so it finds a loving home with an XZ series enthusiast hopefully.