How effective & efficient is radiant heat? Is it hard to do it yourself in concrete basement flooring?

I have only had limited experience with radiant heat in a concrete floor, but I have to ask, heat? In a basement? Ok, what you want, you want. The kits should give sufficient information to help you out. Excessive lime or hard water is treatable, but most treatments involve chemicals that with eventually erode the plumbing, i.e. salt. (yes, even Pex). Efficiency should not be too much of an issue, as the kit you buy should suit the sq. ft. of the room you are installing it in.