I don't understand them well enough to argue strongly if/why they are better than X.
But I like them as an idea. They relate to a bunch of other ideas that I like (commons, peer production, mutual aid). Seems worth more attention.
And I generally like the idea of non-market alternatives. And the idea of non-reciprocal transactions (although I'm not 100% sure gift economies are considered non-reciprocal).
One thing that makes me a little hesistant though, is the idea that giving a gift produces an implicit debt. If it's built on that intent, it is still built around a notion of debt. Which doesn't sound great.
1. Epistemic status