Vquestor, it may to early to give up entirely on SynthFont but like all the others it suffers from strict adherence to the GM standard. This means conversion of the Yamaha Styles/midis from XG to GM. This is not as difficult today given OMB, M. Bedesem's programs and other software alternatives. This would also be required for sfz+ and VSampler. In the case of SynthFont I could not get the drums to work at all. It wouldn't even play the piano instead of the drums - it did nothing for the drums. While I have not tested Halion I think it two will have trouble with Yamaha drums. This is life.
It is for all these reasons that I still use LiveSynth Pro & sYnerGi GS. Sounds good - works good - minimizes effort. The advantage of Halion would be that I could use one professional class soft synth to do everything (lead/melody voices & accompaniment).
I know of no conversion program for DXi to VSTi.