Both are definitely worth playing, and head & shoulders above the main game IMO
Agree. Obvious CDPR thought much the same in retrospect considering you can start both without touching the main campaign.
When you have a set protagonist like a "JC Denton" or a "Geralt of Rivia", you need to keep the game short and sweet - heavy on detail. Witcher 2 is their best work overall.
They focused to much on scope for Witcher 3, which really crippled it. Aiming for an RPG that large, really needs to give the player more motivation for replayability - factions, classes, better exploration etc.
Fingers crossed they've remembered this for Cyberpunk - really no excuse given the source material.