Hey andi_aut,
There's a new KTV place next door to the Crowne Plaza in Changshu. I haven't had time to try it out yet, but I did stop in to gather some info.
One of the ladies at the front door spoke English well enough to fill me in- it's got a sauna downstairs and "sleeping with girl" on the 1st floor. She said it's about 200RMB for sauna, massage, etc downstairs, and about 700RMB for 3 hours "sleeping with girl" upstairs. I walked around down in the sauna area and it looks pretty clean.
I don't know any of the street names, but if you go to the Crowne Plaza, it's on the corner between the CP and the main street. There's a huge multi-color flashing neon sign facing the main street and the entrance is on the opposite side of the building from the sign (facing the CP). I think the sign says KTV and everything else is in Chinese.
Report back if you go- I won't be back to Changshu for a while, when I do get in there I'll let you know.