Thanks for the input, guys!
@Bluebird and Frankie: yes, I've seen some of the discussions on the Sib x hamata, and I agree: based on the leaf structure, it appears that the hybrid was mislabelled. They still look pretty cool, though! And yes, I'm always on the lookout for SG'd plants!
@SK: Glad to hear these plants do well for you, and others - that's my main concern, that they can do well for practically any Nep grower!