I got a spool of Polycarbonate (PC) from E3D-online when working on the OpenRC Truggy a few years back. Basically this enabled me to get the project to a level of durability that i had envisioned when starting the project and while that was amazing in itself it didn´t magically happen over night. While this filament makes for extremely durable and tough parts it van be quite challenging to print. Once you got it figured out though it can be a valuable resource for those parts used in demanding applications. At the time there wansn´t alot of information about 3D printing PC which meant alot of trial and error. Luckily that´s not the case anymore and there´s lot´s of resources available this website being one of them.
Extrusion temperature
The E3D PC needs to be extruded at a higher temperature 
than many of the common filaments we usually print with. Between 280° – 310°C is the recommendation. I have only printed it in a MakerBot Replicator 2X which has a max extrusion temp at 280. Luckily this still worked out fine with the parts coming out nearly indestructible. It´s also worth noting that the 2X have a all metal hotend which (depending on hotend design) might be needed to reach desired temperature. So check this before ordering aswell as your printers max extrusion temp. My plastic extruder block actually cracked after printing alot of PC. I´m guessing it might be due to the long exposure of higher extrusion temperature.
Bed adhesion
The recommended bed temp is 110°C but i had to increase it to about 120°C which worked best for me. I basically only tried two things for bed adhesion and they both worked well. One was the classic home made “ABS slurry” and the second PVA. I 
usually don´t like to use a raft but for smaller or longer parts i used a raft and it worked really well.
Ventilation
Please see to it that there´s adequate ventilation in the room where you are printing PC as it can produce toxic fumes.
Conclusion
While the E3D Premium – Polycarbonate have enabled me to produce the toughest and most durable prints i have seen, i try not to use it too much if not really needed. It´s challenging and there´s the fumes. Also, i´m not a fan of the part where alot of 3D printed waste in these kinds of plastics get discarded and thrown in the trash. However if the top priority is a durable, tough part with good 
heat resistance, this is defininitely what your looking for.
A alternative is Polymakers PC-MAX which is a PC blend from Polymaker. It´s easier to print but is not as durable and doesn´t have the same level of heat resistance. (Article coming later)