Pretty much what Jervon said. Reset the level to one as well as perks/stats acquired from level-ups, keep your cosmetics and inventory unless it's Quest/story related and has good reason to not be available when starting a new game. You'd have quick access to things and would still have to level up to use a maxed out cyberware setup. Maybe reaching here, but a new ending/story option like replacing Johnny Silverhand with a completed game's V, only available in NG+, would probably be awesome.
