Ended up buying a basic mfk700, plus the 0 degree base (I can't see the point of a 1.5 degree base as it's obviously no good for solid lippings). I was expecting it to fit perfectly, but when attached there was a significant amount of play between the router body and the attachment, because the tool doesn't locate properly against the casting of the base - the face it locates against is not machined flat and being a die casting was far from flat out of the box. Rang Festool, who just suggested taking it back and exchanging it -
not very helpful as that would be 3 days to change a part for something with the same problem, so I decided to stick it on the lathe and sort it out. Bolted it down onto the top slide, stuck a milling cutter in the chuck and faced it off properly, as Festool should have done in the first place.
It now locates correctly against the base plate of the router, no wobble at all.
End plate of router body, showing the locating pins:
Newly machined face of 0 degree base, the face now locates accurately against the arrowed face on the previous photo.
I removed about .010" total, around 0.25mm
Seeing as I've now butchered the base I might as well finish it by
http://festoolownersgroup.com/festool-tools-accessories/usefulness-of-the-0-degree-base-unit-for-the-mfk700/msg155030/#msg155030hacking out a bigger slot for the bit.