Shadyj
As you know, I can vouch for the Monolith 10" sub because I bought one !
I too had Klipsch subs, although not the downfiring kind (mine were front firing).
I do not have the linguistic skills to provide an audio review, complete with purpose prose and alliteration.
But, I will say my Monolith 10" is two thumbs up from my music room.
Like BSA said though, if you have a big room and a smallish budget, doing a DIY sub may give you great joy and the Hsu subs are legit as well. You are in a position to make great choices either way you choose.