Questions to ask when considering underfloor heating;
are you Roman?
Has the specialist company filling your underfloor heating been in business for over ten years trading under exactly the same name?
Does the contract state that they will guarantee it for at least over 25 years?
Does the contract state that they will rematch like for like flooring should any area fail?
Does the contract state that all other refitting or replacment will be covered?
Does the guarantee cover fire damage from system?
Are all the parts of the system covered?
Does the guarantee only kick in for whole system or part system cover?
How many times will they come back and fix it, is there a limit?
Will you be ok with disruption should the floor need to come up?
Do they out sourse their insurance policy?
Does the system cope with hot spots should you want to move furniture around or have elderly dog sit in same place 24hr a day.
Oh and the warranties are not worth the paper they a written on, and all the companies are Ltd., but ask the questions anyway as it funny to watch people be economical with the truth when you get the specialist in for a quote.
Honestly don't go for wooden or cork (check the modern stuff out lovely oblongs in whatever colours you like and the most environmentally friendly product ever) on a well insulated base, if you want a warm floor.
Having run high end builds for a very long time, I am very careful never to be responsible for any underfloor heating, if a client does want to go down that route, we give them a longer version of the above, and get in the specialist which because of the nature of under floor heating we tend to see often as it so problematic.
On the other hand it is great for business, as often we get new clients who have spent a lot of money buying a lovely place with underfloor heating it develops faults and then find that having all the floors up leads to a rebuild, same as the cavity wall trend, wonderful work creation scheme.