All depends... The 5XX series were very good at pro tasks mainly because they had unlocked some of the pro features (call it a mistake, misconception or a error on the nVidia side if you like). But they are nowhere close to the 7xx series now, so the advantage is over...
By the rule of a thumb - a decent midrange pro card does a better job at 3Dmax as the best gaming ones...
But choosing a gaming GPU over pro GPU is more or less a personal option - everything has some pros balanced by some drawbacks...
dunno.. i'd say>
1, applications/games: Pro cards are way better for work and not as good for games, Gaming ones are excellent for games and decent for work...
2, software/hardware: Optimized drivers. hardware frame sync, etc... All available only to Pro card....
3, compatibility: certifications - you won't see a gaming card to be certified for 3Dmax, Maya...
4, stability: Gaming cards are build for speed - which is good, Pro for stability in mind - do as much as you have to without worrying that your card will shut down...
5, support: Pro cards have premium support, better drivers, etc. compared to Gaming cards...
6, life: Pro cards tend to outlive the Gaming ones - one usually changes the Gaming Card every year /or at least every other/, Pro cards will last even 5-6...
7, price: Pro costs more./. way... more...
There are 7 points, assign to each one a letter:
>P for Pro - if you know you will use and need that feature /and or if it applies to you/,
>G for Gaming - otherwise
Count them and get whatever falls out
In the end you are only limited with your budget - and an i7 /or a Xeon/ with 32 GB RAM will eat a lot of it