I can get vx10 or ct120 for bout same $ (both used)
Which model is older and would that really matter

I have a CT-120, bought it about 10 years ago when we lived in a smaller home. Used it after we moved in a HT area of about 6000 cf, it was still an acceptable sub for that large area. (It has since been replaced by a JL Audio Fathom f112). If I remember correctly I paid about $600 for it back then. If it were me I'd go with the 120

I actually have a VX10 in my smaller HT but if memory serves me correctly the CT120 should play lower and louder.