Is under floor heating less efficient to run than radiators?

[berlininvest]

Assuming it is driven by a condensing oil-fired boiler,

is under floor heating less efficient i.e. burns more oil for the same comfort level,

than standard radiators?

And roughly what kind of percentage difference in efficiency are we talking about?

Real world experience is what I am looking for please.

Assumptions:

Sub floor is well insulated.
Walls are well insulated.
Good thermostatic controls and timers on each system.