I just got him after completed the Okeanos Chapter.
He is a good 3* Servant? Should I up him?
He also has a charisma skill and is a great support archer as a result with these two skills. I should mention that his second skill also gets rid of mental debuffs which can come in handy(very rarely, but its there). I love using him and Hans interchangeably as my main supports alongside a friend’s Waver or Merlin.
David is a really, really good servant.
He has survivability for himself with the heal+def up, he gives an awesome support tool with Harp of healing, removing mental debuffs (such as charm), healing a little and 1 hit evade, and a good Charisma, which is always welcome, then his NP has sure-hit, deals a pretty nice damage and has skill seal.
Also, his deck is good for arts-chain for faster NP up, and has one of the highest ATK in the 3 stars lineup.
You really should level him up. No Master is good without David.
Yup, definitely a great 3-star. Teamwide 1-hit dodge + heal, self-defense buff + self-heal, and teamwide attack buff for skills, plus decently hard-hitting single-target NP means he covers a lot of bases and gives you quite a lot of freedom for team comps. His 3 Arts cards are also pretty useful to help in raising his and his team's NP bars faster.
He's pretty much the only non-gold support Archer on the NA server right now, and is better at it than most higher-rarity ones (of course, gold Archers usually compensate in other ways, mainly damage output). As long as you're careful not to put him up against too many Lancers he'll serve you well.
David is wonderful while still building your servants with the team evade to protect you from boss np's. He saved the day many times in my early days of FGO. Now that I have a lot more maxed gold servants I have a much higher likelihood of clearing quests before the boss charges np, so David isn't used nearly as much anymore.