I understand talking about the collection Radeon and FirePro. The use of professional graphics cards in servers/workstations determines their form factor - they are usually single-slot. Cooling system of turbine type and therefore quite noisy. I don't know what cooling memory and VRM, but I suppose that is no better than the "civilian" models. Which are specially made for games, that is, assume a large load on the memory, core and power supply system. Of course they use premium components. But agree that leading brands(Sapphire, Asus, MSI, Gigabyte) will use in their cards got hit. They monitor the reputation. But the price have big difference.
For example, a feature of professional cards AMD: "AMD Eyefinity: Drive up to six 4K displays". They have a six port mini-DisplayPort that the average user is not necessary. Of course this technology was a regular card.
The situation is similar with NVIDIA.
http://www.amd.com/en-us/solutions/professional