NH, there was an error when creating G3 that DAZ silently fixed in G8 concerning the eye movements and a lot of conversions fell into the trap. I believe the issue was that G3 and G8 eyes move in opposite directions when the sliders are moved the same way. This F'ed up a lot of converted poses as well as converted characters. For me the key was not to Align All Nodes before doing any ERC freezing. You can align the Pectoral nodes if you are converting a character with large breasts to keep the nipples in alignment. By not aligning all nodes you get the alignment that your base character (either G8 or G8.1) has for all the unaligned nodes. I hope that makes sense.
The other issue is that we have to do all conversion work on Base Resolution models. The DAZ PAs have tools that remove that restriction and work on models in High Resolution. But the reality is that you can come out with completely acceptable conversions if you know some of this information in advance.
I have also tried all manner of conversion scripts, and so far for me, the one that has caused the least amount of issues is XTransfer. Of course I hack and edit the resulting .DSF files and now routinely use XTools Shape Splitter to separate head and body morphs into separate dials.
I am also hoping that there will be a real G8 to G9 character converter before really jumping onto the G9 bandwagon. Personally I don't give a shite about pose conversions.