It is not. I have yet to have any connection issues, it seems like it's locked solid in place, no movement if I push on it. I use it mostly with a T2 at work, with a 510/ego adapter, since the T2 draws too hard without it and they very rarely leak on me which is something I don't need to mess with while at work.
This is for the Spider, I don't know if version 2 has a spring loaded connector.