The hard data has been around for years, and is fairly easy to find. Not every blog post needs to have an accompanying statistical analysis.
Cost: http://www.eia.gov/forecasts/aeo/electricity_generation.cfm -- on an LCOE basis, Advanced Nuclear is cheaper than everything but natural gas and that's entirely due to CapEx costs to build new plants -- which are what the modular nuclear companies that Sam's joining are working on fixing.
Density: https://en.wikipedia.org/wiki/Energy_density#Energy_densitie...
Predictability: Can be assessed by the capacity factor of plants that are running, the EIA publishes monthly data; http://www.eia.gov/todayinenergy/detail.cfm?id=14611
This seems to at least be partially taken into account in the "Total LCOE" numbers (sorry, but this report doesn't seem to have much as far as exactly how these numbers are calculated). Without subsidies, Solar PV is about 30% higher. However, when you look more closely at the actual ranges behind the averages that are the primarily cited data, you'll find that the Total LCOE estimate ranges for Advanced Nuclear and Solar PV actually overlap. The "minimum" Solar PV estimate is 97.8 and the Advanced Nuclear "maximum" is 101.0.
The claim that atomic energy has major advantages over solar is not borne out in this EIA report. In fact, the report seems to show that solar is highly competitive with almost every generation source and actually has a huge advantage in ongoing maintenance costs, being practically at the bottom.
I haven't investigated the other links yet, since the first one didn't seem to pan out.
Above I illustrated my calculations on just one hour of battery backup for US grid with lithium ion- would require 10x annual global production of lithium. Generally cost of battery backup looks like 35c/kWh and has limitations on duration so it must come back to fossils.
Solar makes a lot of sense if backup/storage/smoothing weren't needed since pv has gone down in cost. It still makes a lot of sense in many off grid applications, and for instance in my home we have solar concentrator lights and I would love to have solar water pre-heaters in the summer. But for on grid the capital requirements are much more complicated than generally illustrated, and ultimately the environmental impacts are greater than apparent at first glance.
For short term very high flux power conditioning they've got uses. For long-term storage not so much.
Seconds to minutes is likely their effective range. Not hours to days.
Solar has the advantage of trivial decommissioning, but a huge disadvantage in requiring things like storage, overproduction, long distance transmission, and smart grids, all of which raise its effective cost if you're not putting it on top of a fossil or nuclear-based power grid.