If you get in early before the herds you get the best gains. 

However, like any convection or radiant heading system, they are slow recovery which makes them a poor choice for a draughty, un-insulated building.Here gas, oil and electric are all comparably priced (expensive), which helps to emphasize (IMHO) that the biggest payback comes from air sealing and insulating regardless of how (in)efficient the heating source.  

congrats on your venture I wish you the best of luck with it.. also its ringing endorsement with the uber competition and herd mentality that is following MF these days that you guys pulled this off.... your to be commended. 

I have used it for years in radiant floor applications and it has been used in Europe for years, so it is well tested.

The house has a defunct radiant ceiling heating system.

Extend the life of it by apply aluminum paint ($100 or so per 5 gallons) on the roof as it then reflects the radiant heat from the sun and keeps the roof from becoming too hot especially in the Summer.

If you have no radiators and can't use space heaters, you'll have to install radiators or figure out another radiant heating system -- I assume that you don't want to add duct work and reconfigure furnances/boilers.

@Alexander Felice said it better than I can "people make awful choices all the time, in the face of good advice" Call it the institution imperative, herd mentality, whatever you want. 

NEVER follow the herd.

The weak brokers and agents might be thinned from the herds with some automation but that can be said about ANY BUSINESS in the world.The top 20% in any field are in demand and tend to have the highest incomes.