So I got the card and installed, with many 2d games its crash city as expected.
Dremelled off the two caps on the back of the board (actually carefully de-soldered and cleaned up with chem-wick - awesome stuff)
It's slightly better but not reliable at all with about half the titles i tried, It absolutely hates anything by bullfrog for example... I guess I will have to try and source the correct parts and make the rest of the alterations, hope that fixes it up better. Kinda crappy that there's not a definitive guide, seems I have to combine the advice on Ian Stedmans site with the instructions from Jen's... I'll probably raise a support ticket with Amigakit and see what they advise.
edit: hmmm, maybe I spoke too soon, only thing thats actually crashed it at this point is Theme Park, syndicate runs great, very smooth played through 4 missions with no issues, just removing those 2 caps has made a massive improvement!