Not that I have ever tried this much, because my idea of placement was to throw it in the corner, set the level, and let it go, but I have read several times lately, that boominess often is an effect of room interaction. If you don't have to deal with WAF, then you can try moving the sub around the room to see if you can eliminate the boominess. If you have it facing a corner (or corner loaded), you can try and move it away from the corner and maybe down the wall some. I actually have experimented with mine where I have rotated it 90 degrees, moving the port and speaker away from firing into the wall. I was having a promblem with pictures and a shelf vibrating, and just turning the sub stopped these problems, but I did loose some volume. I am by no means an expert, so this could be all sub.
Of course, if you want to upgrade, then by all means upgrade. Just know that if it is a problem with room interaction, then changing subs will not change a thing. Especially if you put the new one exactly where the old one is.