there are a few folks that have the titan xp that might chime in. there was a nvidia driver issue when the pascal cards first came out, but that was fixed a while ago. i think pascal cards are broken in AE for ray-tracing too, and a manual optix update might fix it. puget also released a benchmark article with some pascal cards.
the 10 core i7-6950x overclocked at 4ghz+ with ddr4 memory around 3000mhz and the new asus X99-E-10G WS is probably the best combo. if working with multiple layers of red media a dual E5-2687W V4 xeon system may be better. this puget article shows some performance scenarios with different media types.
Anyone had their hands on one of these and how does it fair with Premiere Pro 2015.1 & 2015 .3?
They work fine with Pr. I haven't run any benchmarks, but the functionality is all there.
The Titan X (Pascal) works as a charm for me with Premiere Pro. The performance is outstanding!