Um no, that's not accurate. It's not a question of "free" vs. "commercial". Some CODECs have patent licenses, and others are in the public domain. That difference is not related to the quality of the CODECs. The G.729 CODEC is an example of a licensed CODEC, and all OBi devices legally support that CODEC (Obihai has paid the license fee). It's not very useful anymore, as it was originally used in the days when internet bandwidth was expensive and constrained.
If you are calling regular telephone numbers, the international-standard and license-free G.711 CODECs provide the best call quality that the PSTN can handle.
At this time, there are several competing wideband audio codecs; some public-domain and some patented.
See this table for a comprehensive list (including many that are not used in telephony):
https://en.wikipedia.org/wiki/Comparison_of_audio_coding_formatsThere is no point to using a wideband audio CODEC with an OBi ATA over the PTSN, since the telephones you could plug into the OBi's RJ-11 jack don't support wideband audio (also known as HD Voice), and the PSTN has a limited audio range.
If you want to make pure SIP VoIP calls from one SIP phone to another, the OBi IP phones support the wideband opus CODEC, and they have built-in HD audio amplifiers and microphone/speaker components. Some Grandstream IP phones also support opus.
Opus is royalty-free and it is becoming the de-facto standard for wideband audio.