I'm pretty much in the "have everything I need and would only like a 64-bit sampletank plugin" camp. I'm even one of the few and strange ones that like the current interface. So an alternative to upgrade to a bare bones 64-bit version for cheap would be my preference, I'm not even sure I'd like it to be more featured. The edge Sampletank has on Kontakt (for me) is the simplicity while still having a lot of flexibility.
At the same time I'm not a fan of the custom shop idea. The custom shop has kept me from using the latest incarnations of amplitube. Including upgrading and using the free versions (even the bonus featured received with hardware). It's just a personal preference, nothing I want to argue about. IK are in their right to push the idea and it seems successful.
Will be interesting to see the new Sampletank anyhow, but I don't care that much when it gets here.