Thanks for all the replies. Here are some answers to the questions.
- I do shoot film, but I use 6x7 cameras for that, so film isn't a concert (I've never ran a roll through my Contax 645).
- Continuous lights aren't really an option. I like to use them on occasion, but since I'm using a CCD back, I don't like going below ISO 200 when possible so that typically will mean strobes.
- I like the Alpa cameras but I'm not a fan of Rangefinders. Also, if I have to buy new lenses anyway I don't think it's much of a savings. And, I don't really want to carry two kits.
- I'm not doing anything with super high speed photography, so I doubt I need more than 1/500th - 1/800th sync speed. I just definitely need more than 1/90th.
- The lenses I use most:
80mm (80% of the time)
120mm Macro (10% of the time and I love the Contax 120mm)
55mm (5% of the time)
45mm (5% of the time)
Also, there has been a lot of mention of auto focus. I never use AF. I'm always manual. BUT, if one (or both) has a great AF system that is more accurate than I've had with other systems (Contax and Canon) then I'd be open to start using it. The main reason I've never used AF on the Contax is the center focus point. I don't like to focus and recompose. So the H5x having multiple focus points sounds appealing.
A big draw is the "all in one system" idea with a Phase camera and a Phase back. I know the IQ180 isn't quite as "all in one" as the IQ380, but it's more of a "kit" than the H5x + IQ180. But it's obviously not a deal breaker since I'm using what is far from a "all in one" system as it is now and have no problems.
This is a concern:https://www.phaseone.com/en/Search/Article.aspx?articleid=2301&languageid=1
"Hasselblad has not offered any guarantee that the H4X/H5X will work well with the Phase One IQ or P+ digital backs, and it is therefore difficult for Phase One to recommend this as a viable solution."
Is this just Phase One spin or is it a real concern?