I'm sorry, but what is a Jonas Quinn? Don't know who you're talking about. Nope. Never happened.
Seriously though, I don't think the character could be more bland. I know TPTB got a lot of flack from the Atlantis cast for not letting them have any say in regards to their characters, but holy hell Corin Namec ruined it for them. On top of that TPTB, instead of using the opportunity to shake up the team dynamics and create a brand new character, made Daniel 2.0. He became everything Daniel was in a few episodes, just needed a lot more food to do it.
I did like the touch of Jack not accepting Jonas for the entire year. Not only was he the audiences' proxy but it also rang true for his character.
I'm not the biggest Daniel fan but I was glad he came back.