Yes, we had two installed in our last home. It was a Barret home with an internal bathroom with no window and an upper landing that was above the level of the hall window and so was very dull. Both were a bit grim along with the pretty grotty spec of bathroom standard fittings.
It is right that it was about £1500 for two which were 45mm diameter I think. I did think about a Velux window which would have had to sit at the top of a boxed in 4 or 5 foot shaft which would penetrate the bathroom and landing ceilings and go up into the roof space between the rafters - not much space for that type of thing.
I think the Sunpipe was neater for the following reasons: you effectively get a round frosted glass lens on the ceiling, looks a bit like one of those enclosed glass light shades like people often have in kitchens, only neater, and no other disturbance in the room. The two pipes were located only about two or three feet apart either side of the bathroom / landing stud wall, the pipes went up to each side of the sloping roof at approx 45 degree angle so they met their respective side of the roof at a right angle. They are probably brighter than a similarly sized velux (would you have a velux only 45cm square? probably not) since they have a lens on the outside of the roof which collects better than just a flat sheet of glass, and the shaft or tube is mirrored on the inside, a bit like a thermos flask. In fact the thing works more like a big fibre optic. I have to say that the tube in the hall way which was connected to the south facing roof slope was very bright most of the time, amazingly so on a sunny day. The bathroom pipe's lens faced north but still totally removed the need to use the electric light and made the bathroom very well lit. Believe it or not, I even used that loo at night a few times without the light on because enough moonlight was coming in to see by (you know how adjusted to the dark your eyes are when you wake up) whereas previously it had been totally black in that room. They are also very well insulated with no discernable change in temperature to the room. I quite liked the look of the little pointy domes on the roof too.
I believe you can buy more expensive types which can include a light (if you want to delete the light fitting out of the room altogether and tuck it in the pipe - can't really see the point unless new build) and you can have an extractor fan in it too. You can also have a blind that clips on to it to block out the light.
Yes it was quite expensive, but I'd say for a room with no windows it improves things so much that it gets well into that area which we all are really seeking in DIY projects: improved quality of life!
I am not a salesman for them by the way...
One final thing - we had a leak, which we were convinced must come from one of these pipes, the company that fitted sent someone to investigate and he could find nothing. I had thought it a bit odd that the leak didn't seem to occur despite heavy rain, but then would appear almost randomly. Turned out that while the guys who fitted had done a perfect job, while in the roof space they'd accidentally knocked one of the ducts leading from the extractor in the ensuite next door and steam being extracted was condensing and dripping out of the dislodged ducting on to the ceiling above... the guy who came to look at it fixed it for us with a shoelace!
The company we used was Monodraught - they were very professional and I know that they have a high reputation among professional construction industry specifiers so are unlikely to muck you around.
I'm quite disappointed that in our new house there isn't anywhere to have one!
