Too bad that the project is in limbo after Coqui (the company) folded. The license limits the use of the weights to non-commercial usage unless you buy a commercial license, and there's nobody left to sell you one now.
I don't know the details in this case, but it seems plausible that someone still owns the IP and thus might be in a position to initiate legal proceedings.
Honestly, I don't think that sounds as human as piper does, but that's probably a function of the voice model files more than anything, fe, en_US 'amy' sounds artificial, but hfc_female sounds more realistic on the Piper samples.
Too bad that the project is in limbo after Coqui (the company) folded. The license limits the use of the weights to non-commercial usage unless you buy a commercial license, and there's nobody left to sell you one now.