Does port location make a significant difference with regard to speaker placement?

Hi all, 

Pondering a speaker upgrade this fall, and with Axpona cancelled I am just going to head out and shop.  If I'm trying to "fix" anything with my current setup it might be some bass muddiness on certain tracks.  I could turn the Loudness off but why, LOL.....

Anyways, as I look for speakers am I expecting too much to say that moving from a rear ported speaker to a front/bottom ported speaker would be worth the effort to clean this up?  My speakers have decent proximity from walls and corners, but suspect I'm not perfect here.  I've also played with absorption behind speakers with some success, some failures.  

So looking for first hand experience in changing speakers and port locations, and the impact on sound, considering same speaker placement.  

Thanks in advance.  

EW