No mate, it would not improve things for the work I do (or, indeed, for the work of the majority of people). For real time rendering and gaming then there's no point in spending thousands on a Pro-level GPU when your mainstream gaming graphics card can perform every bit as well (and likely even better). As
@Silent_Scone has already suggested, that sort of graphics card has use in very specific roles (as does AMD's FirePro range). Of course these pro-level cards can be used for gaming but you're wasting thousands of pounds if that's the only thing you do with it...!
These expensive GPU's are typically found in high-end workstations where stability, reliability and accuracy is more important than it would be for your average user. Hence you tend to find them used for CAD applications, advanced mathematical simulation, special effects studios and so forth. The incredibly high prices reflect the additional features of the cards and, to a degree, help cover the work that goes on "behind the scenes" in terms of the extra effort that goes into developing the specialist drivers for them. The drivers have to be a lot more stable than those we use for gaming and a heck of a lot of development goes into the continued development of driver software / technology; an expensive business. Likewise, the cards need to be incredibly stable when used for hours and hours under high loads; performing calculations, rendering millions and millions of primitives accurately, etc. The cards also have increased internal colour accuracy and reproduction (better DAC's and other components) for those that need it - film makers, movie post-production studios to give a couple of examples. They also have better double-precision capabilities that helps maintain a higher level of accuracy in terms of data that is held and manipulated by the card (basically more bits are available for storage of numerical values hence larger and more accurate values can be maintained internally and rounding errors are reduced). On top of that you also tend to find that they come with whopping great big frame buffers (useful for high fidelity work) and outputs that can drive many monitors. Oh, and usually some support for various inputs, too.
Apologies for the brief and basic overview - dinner's ready and I'm starving! :tonguewink: