Lately I have been experimenting with turrets on my Python and discovered they are incredibly efficient on a ship that is not very agile.
The huge advantage of turrets is that a faster, more agile ship can not outturn your weapons any more. You can keep the pressure on forever. There is only a damage trade off in theory, because your turrets will be able to hit the target virtually without pause, no matter how agile they are.
As far as I am concerned turrets are a godsend for a large, lumbering ship.
All my weapons on my Python are currently turreted.
I have a D3 beam laser on the belly/chin hard point and Pulse lasers turrets on top.
I also tried a Canon and a Plasma Accelerator in the bottom slot, but I was not impressed by the results at all.
My current config does the job very well.
I would like to point out that there is a pause in turret damage out put, it is a intended mechanic implemented by FD as a balance. Though its not huge. There was a thread about the topic a week or two ago.