the remora when moded with the napkin in chamber, is near quiet. This alone justifies purchasing it over the BakPak HOB. As for efficiency, I could only get my BakPak to work well if I added a limewood airstone to the bottom of unit. Have read that if you upgrade the pump to something stronger and or mod/insert a needle wheel impeller (see RC posts on this -- using fishing line), it will produce much better results, however, I was only using the stock Rios. As for looks, if you can see the HOB from the room, the remora is a much better look in my oppinion.
I really like my Remora, PM if you have any questions.