Tried both EXS and Kontakt
EXS works very well, easy to map etc but obviously you can only have one type of waveform.. effectively works as a synth with one oscillator.
Kontakt is much better as you can insert multiple instruments that can be played together.. effectively a synth with unlimited oscillators. Bit more difficult to setup though.
All in all the waveforms sound great, layer a few and they sound huge, thanks.