In order to give you an accurate answer, I guess more info will be needed. When you talk about electric vs. Hydronic, it makes a big difference what you pay a Kilowatt/Hr for power.
That being said, if you are more concerned with long term efficiency, a hydronic system would be better.
If you have access to the underside of your floor, an underfloor tubing set-up is just as easy to install (or maybe easier) that one put under tile.
Onix tubing can be installed in about half the time as PEX, and does without transfer plates, although you must insulate beneath them.
Hot water heats slowly, and evenly, so dont expect fast rises in temps like forced air.
Hydronic does not blow dust and allergens around, and the heat created stays closer to the floor and doesnt accumulate up at the ceiling.
Also, the primary concern in any heating system is this: How efficient at holding heat in
, is your structure?
Thats really the kicker. If all the Btu's created are blowing away, it doesnt matter which you choose.
Wall mounted radiators arent bad, and can be converted to more efficient types made now (if yours are old) and the European designs are nice to look at as well!
If you would like more info on Hydronic heat, electric radiant floor heat, or even where to start, give the tech support at Watts Radiant a call.