Reading Matt's reply I can add that I have an ETrsi and an RZ67. Both have nearly the same features such as leaf shutters. There are two big differences to me:
1. ETrsi has a smart connection for flash. The RZ does not unless you can get special adapter modules.
2. The RZ is a LOT heavier.
3. The RZ has the tilt and swing lens.
4. The RZ has a compensation scale on the side and can do closeups more easily.
Otherwise, I find that they have very similar features and the negatives print up to 16x20 from both with good quality given the same film and process.