I love the Contax 645 system: I still have one and use it. And I also wish phase had continued to offer Contax mount (although I understand the business reasons that they do not). And, as I keep harping on, I wish Phase (or someone) would make a Contax 645 lens adapter for the XF.
All that said: I cannot agree that the Contax 645 body is better or more reliable than the XF, nor that the XF is feature bloated. As to the latter, you can set it up to hide features you don't need. As to the former: the XF has the advantage of faster autofocus, many additional useful features, and higher build quality (putting aside the prism latch issue for the moment, which Phase will modify for free).
I do agree that the Blue Ring lens prices are astronomical, and will add that many of them are needlessly large and/or heavy. That said, the Contax lenses were pretty damn expensive when purchased new back in the day.
And the XF does have a waist level finder.
And the Contax is by no means simple: although it has a lovely analog look and operation interface, everything is actually electronically controlled, just like the XF. Meaning, equally likely to crap out under the conditions that electronic items do. (Excepting the fact that the Contax doesn't have a top lcd touch screen to worry about malfunctioning).
If given the opportunity, there's no way I'd swap my XF/IQ3-100 for an IQ3-100 on a Contax body if price were equal. Again, this is coming from someone who's had and loved a Contax for going on 15 years now.
Yes I agree. The Contax 645 is not feature bloated like the XF and likely more reliable due to its simplicity. It's also available with a waist level viewfinder and has a prism viewfinder that isn't easily dislodged like the XF. And have you checked prices for used C645 lenses? You can buy a whole set for the price of one Phase One Blue Ring lens.