Latolite Ezybox

Hi,

Has anyone used this product: http://www.bhphotovideo.com/c/product/741844-REG/Lastolite_LL_LS2420S_Ezybox_Speed_Lite.html ?

(http://www.amazon.com/Lastolite-LL-LS2420S-Ezybox-Speed-Lite/dp/B00452V288/ref=sr_1_2?ie=UTF8&qid=1355411589&sr=8-2&keywords=lastolite+ezybox)

Is it meant to be used with the flash mounted to the camera hotshoe?  If so, can the flash be used on ETTL, or does it block the flash's sensor so that you have to use the flash on Manual?

Thanks.