Well, the basics of using turrets are that you only need to turret your energy weapons if you intend to shoot stuff that are higher than you ships speed or your basic tracking technology (whichever is highest is used).
So, if you have a standard speed of 4000km/s on your ships and a basic beam FC tracking speed of 5000km/s you will not need a turret to track enemies with a speed less than 5000km/s. The same would be true if the ship had a speed of 5000km/s and your tracking speed was 4000km/s.
You still need your actual beam fire control to match this tracking speed.
In general, turrets are used for engaging missiles/fighters/FAC. Against ships you could for the most part use either ship speed or basic tracking speed and will not need to turret your beam weapon.
Whatever you decide to do should obviously be based on the type of enemy you are facing. If you can build beam ships that can destroy your enemy without sustaining too much damage back then beams are much more efficient than missiles. Missiles on the other hand have an enormous range advantage but when you crunch the numbers they are very expensive to use. Especially when you consider all the logistics support you need and not just the missile armed ship and it's ordnance.
If you can neutralize enemy missile barrages with gauss PD, shields and laser area PD you are very efficient resource wise even if you need to build slightly more ships in tonnage in order to do so.
Also remember that when it comes to using non turreted beam weapons as PD they can actually be pretty decent if you also have a good "Max tracking time vs missile bonus" and are able to track inbound missiles for a while before they hit you.
So, you should not neglect the strength of beam weapons unless you have near unlimited quantities of the resources for building endless quantities of missiles and ships to supply your fleets with them.