I think this nail buffer is good especially for the price. I find it handy that the buffer is four sided so you can simply just flip the buffet around to use the next side. The rectangular shape and size makes it easy to hold and slide over your nails without applying much pressure. I like that the sides are also different colours so you can easily distinguish between each side and not get mixed up.
It depends on how rough your nails are, but i find a light buff for me gets rid of most of the uneven ridges in my nails. I hardly use side one (for filing the shape of your nail), but find that side four wears done much faster.
I have since switched to using ridge filler now that my buffer is worn out. But i would recommend this product to those wanting a cheap but good quality nail buffer.