I can tell you honestly that is will sound good sealed. I have a level 4 with level 5 soft parts in a fiberglass 1.25-1.5ft sealed box and it sounds great. I would rather have it ported but I have no complaints. I don't know how it sounds compared to a Fi Q but he will not be disappointed.
sorry had to check my list from dc,level 4s are still available ,MAYBE, i was told last week that stock on them was very low and when gone no more til dec.i believe he had 20 motors left ,but like i said that was last week,so this week ?