@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.
The @e.email account comes with 5GB of default storage. You need more capacity? Don’t worry, we have several plans available from 64GB to 1TB. https://e.foundation/products/?lang=es
Well, app store it's much like Google's one, while their apps are there too. I use Fdroid for almost everything but a few privative apps I got from app store.
Well I think more or less as conclusions at final look. /e/'s OS it's working day by day to have a more free system. Not perfect now, but they are working on it.