-2- None in the way of technical problems that I know of. Personally, I would replace the original jib with a selftacker as soon as possible. That tramp sheeted jib in simply in the way for proper spi handling and reduces the space on the tramp to unacceptable levels when sailing 2-up. The difference is very significant.

-3- With regard to spinnaker usage I think the boat/hulls perform better with the spi up in all conditions expect the extremely light winds where the spi won't fill. I found the boat to be less dive happy under spinnaker then the orginal version. The only possible exception could be where you overtake steep ways at speed where the non-spi boat would be travelling with the waves at the same speed. In fact the volume of the bows is too little to overtake significant waves at large speeds, The bows want to dig in too much and the mainbeam is a little low on the platform (I have raised my by 25 mm and that makes a difference). However I venture that the orgininal Taipan has the same issues when it has enough power to overtake the same ways with speed and so this difference can only be associated to the spinnaker in he way that it is easier to up up sufficient speed with it to get in these situations. Apart from that the spi Taipan is the same in good and bad points as the standard Taipan, both are a bit tricky when rounding A-mark and going from upwind to a beam reach.