Pioneer
Veteran
If you can manage with the fixed lens, and it's an awesome lens, the GF670, if bought used, it's pretty affordable, and a pleasure to behold and use.
Rolleiflex is nice, but if you are used to RF, you may find the waist level operation a bit cumbersome, I know I did.
If you compare the cost of a new GF670 to other new medium format cameras on the market today it is still very affordable. 🙂
And that lens is certainly drool-worthy.