get the Z623 if you don't care about sound quality and all you want is bass alone.

S330D may sound too sharp to many customers so you might wanna beware.
C5 is just C3 with extra features like radio and such. Think about whether you need the features or not.

I would go for C3 as it is balanced and filled with potential for future

C3 bass is tight and accurate... which also leads to low bass volume
Z623 is a polar opposite of C3

Z623 has an odd 7" woofer while C3 has a standard 8" woofer

by size C3 wins, but by bass volume Z623 wins

I'd vote Soundsticks for sound quality or S530D for large,full sound with power

I don't know how HK SS iii sound like but I expect them to be better than SP2500 since it's music oriented speaker.. I was offered pretty cheap last time but due to "gamers" tag and mind set, and better control so I get SP2500.

Actually, the control pod makes thing a lot easier for me. Unless you place SS iii on desk or you barely adjust the bass. For SP2500, the control pod is just on the table and this is pretty easy for me. Another thing I worry about SS iii is the transparent design. I afraid that they will turn yellowish and I'm more confident with woods than glued acrylic. But so far I never bump across SS iii owner complaint this so I admit I was stupid that time.

If you ask me which one, I prefer SS iii than SP2500. I spend long time with my SP2500 and I think I want to change my speaker.

Okay, will let you know... But, still undecided here too. If I can't find a better replacement, I might stick with SP2500. Anyway, how much is SS iii at Kuching? Last time I was offered RM 600 but I passed. Now sold. The reason I hesitated to get SS iii due to bad review at Amazon. SS iii owner here so silent.