I have a Rockrider 9.1, bought £750 last winter. The spec is good and the frame surprisingly light, x fusion 02 shock, hayes trail brakes.
Already swapped out the bars, stem and wheels and just bought some reba 120mm forks to replace the tora’s. Toras showing no sign of wear and have been up and down cut gate a couple of dozen times at speed without any problems as I live near there. I did quite a lot of research and only had £900 to play with at the time. To get the same spec I would have needed at least £1300 to get close.
I know people turn their noses up at the name but hard to find better value and the current ones look better too, but are £800 now.