They take twice as long in some cases but only use half if not less power. They're also kinder to your clothes as they don't get as hot etc. Also as no element their is far less chance of a fire.
You have to do a lot of cycles to recup the initial outlay, for a large family I say maybe for small, I don’t see a financial benefit, especially for more expensive stuff
Factor in amount of times you run a load twice when overfilled
How do these heat pump dryers compare to condensing machines?
I got the 7KG version when it was 249 a little while ago and I have no complaints so far, seems to do a great job.