Thanks for all the input guys. I understand the compression with the RH450/RH750's and I actaully think it sounds good. Tight & controlled (got a chance to play an RH450 & RS210). And though I didn't have a chance to do an A/B comparo with Markbass - but from what I heard out of the TC stuff - I made my decision 
Perhaps my reqest for a "full and wide" sound was more speaking towards the cab - and the RS210 does sound very full sounding - I wanted full and wide becuase I had a highly touted cab - the Bergantion HD210 which I had which had a certain "boxy" tone to it... very "small & midrangey" sounding to my ears.... it sounded more like a component cab to me. I own and love the HD410 - but the HD210 just didn't do it for me.
Anyhow....
Suprised how much I liked the RS210 cab!
Perhaps my reqest for a "full and wide" sound was more speaking towards the cab - and the RS210 does sound very full sounding - I wanted full and wide becuase I had a highly touted cab - the Bergantion HD210 which I had which had a certain "boxy" tone to it... very "small & midrangey" sounding to my ears.... it sounded more like a component cab to me. I own and love the HD410 - but the HD210 just didn't do it for me.
Anyhow....
Suprised how much I liked the RS210 cab!