A couple weeks ago I decided to try out GPU rendering. After doing some research and talking to a few people, I was steered towards Redshift. Several studios have been using it and it seemed worth trying out. Was simply curious. A couple years back I switched from Mental Ray to V-Ray and the idea of converting my library of assets, again, was not super appealing. But, fun to try something new nonetheless. Anyhow, after a weekend with Redshift... holy $@#*! Running on a single 980 card it was insanely fast. IPR became useful for complex scenes including fog and DOF, seemingly about 10x faster than Vray. And easier... less fuss to manage sampling as the speed allows for the use of high rates and Brute force. And a bunch of other things but to sum up. It is cool and I've 100% switched. Just spent a couple weeks converting my library. Also upgraded my machine from a single 980 to dual TitanX cards. Yay for nVidia... and Redshift!
Here's a quick test I did after converting my library. IPR constantly refreshing as I imported random assets, set up a couple lighting styles with DOF and fog... all in about an hour. Really fun...