Reassure me about GPS before I buy a fenix 6

Am looking for a new running watch and the 6/6X Pro seem to have everything I need alongside sports functionality (music, pulse ox, NFC, wifi etc). My runs always contain a bit of undulating, forested terrain and my existing TomTom always seems to be a few percent under the true distance. Maybe I am getting cold-feet at the outlay, but a few complaints about GPS accuracy have me hesitating on the fenix.

Is it only some duff units that have reports of GPS accuracy issues? Or is it across the board for the fenix 6? Maybe it has finally been resolved by 19.20 and GPS 5.30?

Set my mind at rest please! Grimacing