there are some very strong similarities.
when i was 15-16 i had a number of astral projection expiriences, often times unintentionally. the classic body exit sensations were a pulsating or vibration that would sweep throughout my body, ringing in ears, and red flashes behind closed eyes. if i could remain completely calm throughout these sensation separation would generally occur. somtimes though, the vibrations wouldnt be able to enable me to "let go" in a specific part of my body and i would feel held in my body by that spot. it could be quite uncomfortable actually. i observed the vibrations to be the actual astral seperation sensations.
i have come to believe that the astral realms and hyperspace are basically the same thing. they are experienced in different ways though.