Has anybody had any experience with one of those? Are they worth
using/buying?

Some of our lawn is almost pure moss now; there is too much of it for
hand-raking/scarifying and we can't find any powered machine on the
island to borrow or hire (either petrol or electric) or even, any
contractor who owns a machine and could be paid to do it. The last
resort, would be buying an electric one of our own.

ISTR hearing long ago that electric ones were pretty useless but that
may be out of date.

Janet, Isle of Arran