I'm having some trouble deciding which SLR system to invest in. I currently own a mamiya 6 with all 3 lenses, a Bronica RF645, and a hasselblad SWC. What I've found I'm missing in my photography is some of the things an SLR excels at, which is depth of field preview, faster lenses, and telephoto lenses.

For these reasons I want to buy into a medium format SLR system and have narrowed it down to two, either a Hasselblad with 80, 150, and 250 lenses, or a Mamiya 645 with 80, 150, and 210 lenses.

I'm surprised at the huge price difference between the two systems, mainly the lenses. How do the Mamiya lenses hold up against those of the Hasselblad system? Particularity the telephoto lenses. Is the price of the Hasselblad lenses worth the price difference? I mean the Hasselblad 150/4 CF is $450 while the Mamiya 150/3.5 N is $100. That's a huge difference! I found I could purchase an entire Mamiya 645 system for less than the price of just two Hasselblad lenses.

The other question is reliability. I would imagine the Hasselblad system would stand up to use better than the Mamiya 645. How about the electronics in the newer 645 models? And problems?

I guess I'm just looking for some suggestions and help making this decision. I like square and rectangle equally as much, so that's not an issue.