I'm UK too and I have a low level Abrisud dome cover, not telescopic but a dome nevertheless. We bought it second-hand about ten years ago. It is approx 12 mtrs by 5 mtrs by about 80 cm high. We chose a low profile as we wanted the view of the garden to be as unobstructed as possible.
Keeps most of the rubbish out, some creeps under the dome
Lockable hatch, completely child safe
Equivalent to solar panels, is up to 26-28 C at present, can exceed 30 C
Can swim under it easily, great in the rain
Stops pool freezing
Extends pool season
No lugging covers on and off, just open hatch and step in
Keeps draughts off when in the pool
Very expensive, 15,000+ GBP new
Panels are heavy to lift (we have electric lifter)
A pain to set up vacuuming
Can't brush pool sides easily
Needs removing each year and jet washing underneath
Two-man job to lift and stack panels
Frogs, ants, weeds etc love it
We are considering replacing the cover, with what is not decided. We are getting too old to lug the panels about and my wife prefers to see the sky when she swims. We would love a motorised telescopic or stackable version but the cost deters us. Overall the cover has been a boon, I am relectant to see it go, but age creeps up on us. Any questions just ask.
Thanks Kes. Good to get good real world experience. I think there may be some ways to eliminate some of the issues you mention. And a high profile dome could also solve some of the problems (vacuuming, brushing, cleaning the inside, etc. However, the high profile domes are much more expensive (~$20000 for the low profile domes, $30000-40000 for a high profile dome.
I'd love to get a high profile dome, be able to secure it to the pool surround in a way that doesn't allow pests to get under it, but I have better uses for the $40k.
I like the idea of the cover being a sort of solar panel to help heat the pool!
Since posting I have been thinking about creating a electric sliding deck over the pool however obviously it wont give me a advantage of using the pool on rainy/winter days!
At the moment it stays open - until I decide what to do