Hello Christine,
Over the years Sue and I have had 4 mattress toppers, including one from Raskelf. In general they do a good job for the two of us, who suffer a bit of backache. There is no doubt that I have more pain and stiffness after a night without the mattress topper on.
However, the Raskelf one seemed to be pretty expensive compared to the others, and frankly I don't think it was any better at doing the job. Our last one came from Dunelm at a much lower price and is fine.
One work of warning is that they do make the bed a much warmer place - very welcome in the UK in Winter but less welcome near the med in Summer!
Cheers
mike A