This stuff is highly suggested for a above floor dry install.  Yes, there is Warmboard and Raupanel that are better, but I'm a DIY guy and want to save a few dollars.  Labor for me is cheap because I have the time. I know this all depends on the heat loss calc in the end. I also like the idea that an install can be customized based on heating requirements (unlike Warmboard that is fixed at 12" spacing).  ThermoFin U only seems available through the online store Radiant Engineering. Is this true?  If so, do I also have to buy the sleepers and ends through them?  I'm guessing just the ends but I can even do those myself (access to CNC). 

Also wondering if anyone else sells a similar extruded product for above floor layout at a lower cost.  I'm already guessing that these might be pricey. I'm not attempting to be "cheap," just frugal.