We had electric in our old house. I don't think we could have afforded hot water - electric is easy to install under floor. Really really regret not having it in this kitchen - although food does stick to floor a bit with it.
I would say worth extra expense not to have ugly radiators taking up wall space, so you can be totally flexible re furniture placement etc. Plus quite economical as heat rises so other heating systems spend a lot of time heating the room above your head...
This is the 2nd house that dp has put underfloor heating in the kitchen, last house was kitchen and bathroom, here its kitchen and living room as both have solid floors.
We have the hot water type, it is more upheaval to install and more expensive for the installation (ok dp did it for us!) but far and away more effective both heatwise and running cost wise than hot water.
With the hotwater system, the water is connected to the central heating boiler. So, the floor works like a radiator, once its got up to heat, the water just stays warm and goes back to the boiler and doesn't need reheating much. So you can have it on all day for little more than the cost of the inital heat up. Electric however is just pumping out the full current for as long as its switched on.
I love it love it love it. We do however have a radiator in each room thats underfloor heated as its more of a background heat, we have them turned off most of the year but you need something more for a living room in cold winter spells. Only small radiators though so still space saving.
Think about it, the whole floor warm with the heat rising up evenly to fill the whole room. Not like radiators with the heat just rising from a radiator and leaving the floor cool.
Be aware though that it dries out everything, like wooden or leather furniture, that is standing on it. Also, if you have littluns you need to clean up spills and food really quick or things bake on!
we have hot water underfloor heating, underneath an engineered solidwood floor. it's lovely. re cost, it's definitely cheaper to run (by about half) than the old radiators and boiler which we replaced. And we live in a block of flats so we've found we hardly need to use the heating (maybe for 3-4 months of the year) due to heat coming from below; may be not applicable to you.
I also love the fact there are no draughts, everywhere is the same. You can also plumb it in so you can programme different rooms for different temperatures, depending on how many circuits you do.
However, if you're quite a cold person (like me, circulation issues) sometimes it doesn't feel like there's anywhere you can go to warm up, IFSWIM. I used to hover over the rads when i was cold. That's why i insisted on a heated towel rail