I can't speak for Phase, I've used their cams but never called in for service.
But a leaf back I had issues with had to go to Israel via an agent.
Anything I needed doing for my H3DII 39 before I moved to the H4D50, be that a spring failing on one of the connection pins, to a lens needing a new clutch mechanism all had to go back to Europe.
Before buying the 645z I almost bought a UK model but I called Johnsons, the official Ricoh service centre here and they said anything related to the Z except sensor cleaning goes back to Japan.
But they'll be able to send it back to Pentax for me.
It's a far cry from Canon CPS who'll fix a 1DX in 4 days. But we want these exotic sensors right?
And boy is my 1DX looking a bit long in the tooth now sensor wise relative to everything out there
From my point of view, the service levels are all the same to me (excluding Phase One for the reason I started the comment with). Heck, just have a Pentax service centre in Europe somewhere that can handle everything, that would be great.
As a slightly on / off topic point. It was getting to the point I was worried to use my Hasselblad for fear of a big service bill if it goes wrong. No user should have to go through that experience and I'm reminded that these are luxury cameras for people who make lots of money. A bit like having a baby, there's no point getting one if you aren't committed to supporting it. Now, I have a cam that I can use in the rain, at weddings and has high ISO. I can make money from this one. I couldn't with the blad.
And I will miss my blad when it sells (it's on the for sale section) as I love holding it in my hands and shooting with it.