I had the unfortunate experience of two shutter-related failures on the same 645D, about 2 years apart. Both were repaired at no $ cost to me; the first was done under warranty. The second was out of warranty, but it was a situation of very poor customer service requiring some management intervention to get control of, as a result of which the cost of the repair was comped. Quoted repair cost was ~$1000 CDN in the first instance, and ~$1200 CDN in the second. Same body mind you, but slightly different work involved in the two cases I believe.
In both cases the 645D had to go to Japan for the work. The round-trip took 10 weeks in the first case, which I thought was unbelievable; this was in mid-2012. But it was a lark compared to the second case starting July of last year, in which the camera took 22 weeks to arrive back in my hands. While the 645D was in the middle of that 22 week run to Japan, I also had a failure on my 645Z and then a week later my 25mm prime lens came apart in my hands. They went back as well, and both took nearly 10 weeks to return, coming back at the same time as the 645D. This leads me to believe at least some of the issue was that my simultaneous service cases got balled up together and were batched for resolution rather than being dealt with each on its own & returned ASAP.
These and other Ricoh service experiences have painfully illustrated the extreme opportunity for improvement in service level targeting and service management within Ricoh. Right now, I love the system and still have no regrets investing heavily into it. It fits me to a T and I have no intention of giving up on my kit. But if I never have to deal with Ricoh service again, it will be too soon.
I should say I'm most likely a boundary case, and it would be unfortunate luck indeed for anyone else to go through what I've gone through. But if it happened to me it could in theory happen to others; other than the fact that I shoot in digital era volumes rather than film-era frame counts
there's nothing unusual about my usage profile. So invest in the system if you like and want what it can enable you to do. But be prepared to cover yourself if the gear goes wrong, because Ricoh service is not even remotely operating at a professional level as of Q3-Q4 2014. Because I was mid-upgrade last year, I happened to have 3 bodies at the same time -- a pair of D's and one Z. I needed them, because 2 of them were down in an overlapping period of almost 10 weeks.
Still, as others have pointed out, the $ cost of doing this is at least approachable for people who are able to seriously invest in a medium format system. It's more the enthusiast or pro-on-a-budget who's at risk if they can't invest in sufficient backup gear to cover a major chunk of downtime while keeping on working.