@leodurruti yes, I got an refurbished SG7 since October.

Everything's OK if you know what you buy.
I mean, it's more or less the price for a new one but you have the work of install OS done and you support a !freesoftware company.

About the OS itself, as ghose mentions it's an lineage customized to use their services as Nextcloud, mail, etc.
I just changed the launcher to Zim launcher from Fdroid.

You can find experiences and more info at
https://community.e.foundation/

Feel free to ask more doubts or specific questions.