I have been dealing with Apecs Investment Casting for around 4 years now and have had no reason to go anywhere else.
Their service and quality of product is second to none. The turnaround time for a wax to casting is always on time and I have utmost confidence with every piece I get back from them.
I constantly recommend them to fellow jewellers anyway and have absolutely no hesitation in passing on my recommendation to anyone.
Since they have taken on the CAD/CAM process, again, their quality of product and smooth finish of castings is as good as it gets anywhere in the world with any CAD/CAM process.