I assume you are talking about the electric mats that go under tile just to warm it up a bit, not a radiant hydronic system meant to heat your whole home...

There's been a lot of talk about the electric systems in the bath forum, general consensus is very positive IF they are installed properly. It's pretty easy to damage the wires while laying tile.

Of course, cost would depend on the size area you are doing, but in a large kitchen you could probably just do the areas in front of stove and sink.

The temperature of a tile floor is very dependent on what lies below: tile over concrete slab in a cool climate really seems to suck the heat out of you.

But if its over a heated basement, it isn't bad at all...

THen again, I'm a member of the Society for Barefoot Living [http://www.barefooters.org/] and rarely wear shoes indoors or out [my skiboots don't count ;-) ], so my standards are different from most people.

The electric powered floor heating systems should not be expensive. There are several different systems in the marketplace.

The hydronic systems probably cost more initially...but they are tied into your primary hydronic heating system (should you have one)...and those are fueled by natural gas or oil.

Underfloor heating systems are very comfortable.

We have two heated tile floors. One is in our bathroom and the other is in our front porch. They were not terribly expensive and worth their weight in gold. They use little electricity (equivalent to running a light bulb).

It is such a pleasure to wake up in the morning and have my feet hit that warm floor. The bathroom heater is NuHeat. It comes with a thermostat that can be set to go on and off. We usually run it at night and shut it off in the morning. (The tiles will hold heat for quite a while.)

We used a different brand in our front porch (it was a bit cheaper and we did not buy the programmable thermostat). That one emits a wonderful, steady heat into the room. You may well find that you will be using less heat in the room.

Word of caution - think out carefully where you want the heating pad to be installed. You do not have to do the entire room, but when your feet hit the area that is not heated, it is COLD! Also, you do need to have NuHeat installed by a professional or you will void the warranty. You can check out websites for other brands. The heated tiles are a luxury you don't want to miss!

Also consider potentially having to add a circuit for electric floor heating over a larger area (a kitchen is likely to be a bit bigger than a bathroom).

Just a thought.

-Roger