I am a little scared of the render times I am seeing here. Granted, we all have a very different threshold for quality control. Having come from Neoscape where quality standards are set really high and having moved on over to a traditional architecture company for whom I am their first rendering artist, having to find a balance producing images at the last minute with no render farm, has been an interesting juggling act.
With that in mind, this is a quick proof of concept project I turned around http://removed using Pano2vr Pro. Highly recommend it by the way. I tried KRPano and this is just so much more intuitive to use at the moment at least. The panoramas were 10x5k and took 1 - 1.5 hours to render. Having stored the HDRI contribution with irradiance, I was able to cut down on that time from 5 hours. Yes, the shadow quality is not the same, especially to a trained and discerning audience found here. However, proving that this is a viable form of communication that does not necessitate more resources and more time on the part of the firm, was the main objective.
Personally, I can die happy, and probably somewhat tormented, if we could have infinite/vector like zoom on our renderings. Until then, drawing a line on quality vs time vs optimization will have to take precedent.