For me, depends on the light and situation.
If the light is about to turn green as I approach a stack of cars - I'll stay in line.
If there's a wider paved shoulder - I'll move forward. I mean, cars pass me - so I'll pass them within the same space I'm riding in
If the light is going to be red for awhile, and there's a stack of cars... Typically, I'll lane split (if there's space) for a left turn lane and stop in front (still lane splitting).
If I didn't do this, there'd be quite a few pissed of people that miss their green because I can't mash up to 25mph in 3 seconds
If I'm not going to lane split, I'm sure as hell not going to let people pass me while making a left turn
