I used to own a Contax G system: G1 and G2 bodies, plus 45mm and 28mm lenses. The cameras were an absolute joy to use: light but solid, beautifully made, quiet for AF cameras, full-featured, compact and very ergonomic. The lenses produced superb photos, especially on colour film.
But...
I ended up with lots of photos from the G1 with missed focus. I was quite surprised and disappointed with this because I was well aware, having read a ton of reviews, that I needed to be careful with the focus point. I found if there was any movement at all, that the camera would only hit focus less than half the time, so it was only reliable for static subjects.
Anyway, I read that the G2 was 'better'/easier to focus, so I picked one of those up in the hope that would improve things. It didn't. I had exactly the same focus issues.
Next, after only a couple of months of owning it, the G1 stopped focusing the lenses altogether. It just made a grinding noise and had to be switch on and off a few times to take a shot. After a day or two of this it wouldn't focus at all.
It went on eBay for parts.
A few days later I switched on the G2 and some of the lights inside the viewfinder didn't come up. I cycled the power switch a few times and everything was fine, but that was the last straw with the system for me. The G2 and lenses went on eBay and that was that. I spent the money on an xpan. Another electronic brick that will die one day, gives the same incredible image quality, but one which I can focus accurately every time, and offers a unique experience that no ordinary 35mm camera can match.
Maybe I just had bad luck with my Contax G? To be honest, if I was rich and had cash to waste, I'd buy another full set (G1 body, which I preferred) and take the risk. It was a cracker of a system that lives up to it's hype in terms of image quality.