There are lots of bad radiant installs out there. Either people do a bad job on the system install, or they don't bother to see if the room can be heated with radiant heat in the first place. A drafty room with lots of glass is a good example of a room that probably needs more btu's than you can put through the floor, at least without making the floor feel like the beach in July. Sometimes the "great room" may need a length of baseboard to assist the radiant in cold weather.
Do your homework first, and that means a heat loss calculation to see what the heat load of each room is.
My neighbor has a ~1600 sq. ft ranch that was build in the 1970's with electric baseboards. He installed pex with aluminum transfer plates in the entire house, and put a zone of baseboard in the breezeway. I think most of his house has laminate flooring, and there is a little bit of carpet. He has been very pleased with the results.
My uncle has an addition on the back of his house that was always chilly. He ended up putting a "quick trak" system down, which is basically a subfloor that has grooves in it for pex tubing. The pex gets run and glued in place, and then the flooring goes over it. He used some sort of hardwood, and the room is very comfortable.