For the most part they are re-badged cards hardware wise. Nvidia has a habit of creating drivers for the Quatro that allow for better Open GL support. They wont work on the gaming cards unless you re-flash the firmware.
I just find it strange that i havnt seen these cards around or talked about much, and how they can justify being so expensive.
These cards aren't for gaming.
The added cost is usually associated with the cost of specialized professional drivers as well as the certification these cards must go through to be allowed in some workstations for the company to get their ISO certification, etc. As well as much higher level of tech support.
In general they are poor gaming performers because they are usually clocked for durability and reliability not raw top performance, and often when they do do better in a game closer inspection shows rendering anomalies under those scenarios. Here's a benchie under 3Dmark;