we fit electric under floor heating in every bathroom/kitchen we do
and have it at home to

you cant beat it, when im at my birds house she doesnt have it and i hate showering at hers cos when you get out the floors so damn cold. lol

and it works fine on large floors to, if done properly.
we use thermonet.
and you need to get it on the matt. even if it is a couple of quid dearer its well worth it.