I was looking at picking this up.

I have the JP V3 Premium edition.

From my understanding of the website there is an upgrade pack that will take me to V5

But I was concerned about OS requirements. Does anyone have V5 running OK on Non-Japanese Windows?

Also is it still possible to manually change the bin files to get English?

Hi Greygor,

V5 runs fine on normal windows, that's not a problem at all.
We also are still using edited bin files, so no worries there either. You'd just have to edit the bin file yourself, I'm afraid, as we're only maintaining the german version.

Greetings
Sebastian