This is an office interior that I have tested, but it's a tad bit noisy and render times are slow. 15+ mins per frame on 1 GTX980Ti.
Below is the sample render and kernel settings..


Kresimir Jelusić was kind to share this comment in facebook:
caustic to 1, gi clamp to 0.5. coherent ratio 0.3 - turn of alpha shadow (it's for alpha maps to generate a alpha shaped shadow, and you don't have any and it speeds up render)..
glossy - probably to 4 - as long as nothing glossy looks black
- your render is now 50% faster and less noise .. smile emoticon
- yes, why isn't it like that on default, it's always like that with all softwares.. may affect the look of the scene a bit, so tweak those things -
GI clamp is how far the tiny lights reach, so it just cuts of the non contributing samples that just generate noise
- coherent shouldnt go more than 0.3 cause it doesn't make any difference (if you animate it may cause flickering if not enough samples)
Now I am experimenting with these suggestions. Definitely faster, but I plan to animate the scene. I tried these settings and I get some flickering.. Any help would be appreciated.. Thanks guys!
Btw, I'm using the 3ds max plugin, with 1 980Ti, and 1 Quadro 4200 for display.