Wet Underfloor Heating

[pilates]

Just about to start a kitchen extension.

Would it be worth installing?

I understand the electric would be too expensive especially in the climate we are in.

Have you got it and regret doing so?

Depends on your particular house, OP. I had a very cold barn style kitchen, with a concrete floor and an 11 foot high ceiling, which was freezing. It would have been prohibitively expensive to drill out the concrete floor to put in pipes for a wet underfloor system.
However, there was a massive difference in warmth just after putting down thermal boarding as an insulation layer. I had a dry electric underfloor system installed over that, with stone tiling on top.
I don’t find it at all expensive to run, as I only have it on during the winter. The rest of the year, I just use the one remaining kitchen radiator, which is connected to the house gas central heating system - and often don’t even need that, despite living on the edge of the Scottish highlands.