Did you mean to say, you sold the TSW 120 to get to a better sub ?.. Yes
When using 2nd RCA input on the sub, the SPL increases by +3dB without increasing subwoofer volume knob, which is the same as using a single RCA input on the sub + raising the subwoofer volume knob..
Best thing once can do is put the sub in ideal location, according to your room dimensions to get best response..
Between the two, it would be hard to suggest one over the other.. I have dual SW10 v.2 and the lowest response that it could in my room was 22Hz.. It is also from the higher series, platinum range.. TSW 200 being a 12 inch should be equally capable.. If the price difference between the two is not much, then go for SW 10v.2..