I look to Hunter for this answer as they have always lead the way in terms of smart water products and education. We see pictures of spray heads throwing water into the air and the word "vaporization" comes to mind. We see the new nozzles coming out with larger droplet sizes, touting better efficiency for that larger droplet size.
Since sub-surface irrigation could eliminate all of the "droplet" size concern you are apparently interested in, it seems logical that any water lost to evaporation from wetted surfaces (soil and plant) is wasted water.
If the universities were to finally establish what those spray losses were, be they 10%, 15%, or 20%, wouldn't that force us to reconsider our collective contention that irrigation efficiency of rotor systems approach 80%, and that micro-irrigation systems only improve irrigation efficiency by 10 - 15% ?

I agree that sub-surface irrigation appears to be a great way to irrigate turf, but in reality, it has not proven to be a viable solution for larger areas. I've seen it used in narrow strips (4-feet wide or so...) with good results, but bigger areas than that have shown me poor results. Installation is critical, and soil type becomes a greater factor. I've seen jobs that have "striping", and others that even with a little slope, have pooling at the lower elevations--gravity still pulls that water down the hill. Not only that, but you can still waste a lot of water by running the system too long---negating any efficiency.

We have seen numerous sub-surface turf systems go in in the last 5 years. For the most part they are working, however "WATERSAVER" has it right about soil type and slope. One other critical factor...qualified and competent installers. Since Netafim is the only company I know that has a product for this application why aren't they promoting it?