It all really depends if ur buying all the components for a htpc, or ur using gear u have lying about to make one.
The size, or shape, of the unit here wouldn't fit into the htpc I've got at present. It's more the shape of a squashed vhs-video unit - to that extent, the options are to really go with what is supplied with the case. It works, can't remember off-hand if it's 300/350/400 (might be a CiT), but it is a p4 designed psu, with optional replacements coming in the shape of some obscure ebuyer.co.uk stockers. 4 pins to the Q35m mobo has worked to this point.
So really, even with the psu being aimed at the smaller case market, u do have to consider the cases this could limit u to.
Imo too, being as this will not be used (or meant for should I say, cos people do some strange things) in some enthusiasts oc'ing, large graphics, loads of drives, rig - it has a limited appeal to the small case people that I don't think warrants a costing of £45 necessarily.
Having said that, it performs close to the quality of a regular atx of similar wattage. Therein lies the reason u would have to submit.
More than anything tho, I like the idea that the option is out there. Too many things pop-up during custom builds, that hamper what u might want to do. Having the shorter depth is great without the loss of quality.
Great stuff.
(another thing this will be good for is replacement psus for dell/compaq etc builds that often have a small-depth psu in them. if u try a regular one in them, u find the dvd drive doesnt fit. great option)