I picked one up for 10p from a sales bin at PCWorld - for this price it's ok - for the full rrp it's appalling value for money.
The plastic base into which you secure the HDX is good quality and a good fit, it holds the device firmly and and all buttons and ports are easily accessible, the speaker grills are placed correctly and have no effect on sound volume.
The fold-over cover is a little flimsy and can be easily bent out of shape. The fabric part of the cover is a dirt magnet, mine is already stained from a little horror picking it up with her grubby, sticky little fingers. If it was leather or plastic it could be wiped clean but once grease gets into fabric the stain is going to stay.
The case can hold the HDX at about a 45 deg tilt (middle groove) in landscape but it is liable to slip out of one of the 3 available grooves if there's too much movement. There is no tilt facility in portrait.
For the rrp I would have expected automatic on/off when opening/closing the cover but no you don't get this which is a shame - this omission and the use of an elastic band to secure the cover in the closed position go to make this case poor value for money.