The head from a BOSS would be nice but not seen anything from a BOSS listed for some time now, seem to be getting very rare.

Whereabouts are you BTW ? ;)

Yes i decided way back in the beginning to go ahead because I just cant fit anything bigger than a manual BP in the shop - no head room at all. Yes it cost a lot but I have had a blast doing the conversion, learnt a lot and still have a usable machine to play with.

The Quill connection I was not happy with from the outset - its a terrible weak spot, unless a much taller connection is made to the quill to spread the load - this then reduces Z travel respectively and I'm already seeing the bad side of poor Z travel and i only lost 5mm from standard!

I think there is some redemption in using the quill rack/pinion - it's the strongest method and as long as backlash is dealt with should be just as accurate.