Forced hot water should not be a viable alternative to electrical floor heating in typical situations. These systems basically serve different purposes.

Electrical floor heat should be in a small area where you want a floor to warm up quickly like a bathroom. Hydronic floor heating is for maintaining the temperature of the room over a longer periods of time b ecasue it is slower to heat up and slower to cool down.

If you install electric floor heat be sure to buy the mat from the tile manufacturer and get a warranty for the entire system.

Our electrically heated floors in our bathrooms are 40 years old. It works so well that it's actually been a detriment to us updating the baths. I don't want to keep the same floor tile, but know the heating system would be destroyed if I attempted to remove the current tile. So I'd have to say that it will still be working long after you find yourself frustrated at the datedness of the baths.

What is there to go wrong on electric mats. Resistance electric heating is very durable. Whoever said otherwise is yanking your chain.

The weak points are the embedded temperature sensor and the thermostat on the wall. Thick cable warm floors request that the sensor be in a conduit which makes it replaceable. Look at Alcatel/Nexans and maybe DanFoss thick cable designs.

If someone has a 40 year old warm floor the cable will be a thick type mounted in the mortar bed and not in the thinset. It is possible to remove the tile leaving the mortar bed without damaging the cable.

The Nexans cable has been sold for decades and can be used to melt snow in walks and driveways and heat entire homes.

Here is a link that might be useful: Alcatel/Nexans thick cable info