Neoprene rubber under bottom plate

Hello , I have a question about decoupling the bottom plate of the inner leaf from the concrete slab. I am building in my basement and i have read it here before where it was recomended to just build the new stud walls directly on the concrete slab. My question is 1)How much isolation do you lose from the flanking path that would be created by doing so,since the rest of the house is connected to the slab in some way? 2) I found a rubber company near me that i could get 1/8'' thick neoprene rubber that they are willing to cut 3'' wide for me,is this a good thing to use to decouple the inner walls from the slab? Or does the rubber has to have a certain specification like x amount of pounds per square inch etc. 3) Green glue company sells a product call Joist tape is that a better solution than all the above? Or am i going over board about sound transmitting thru the concrete slab to the upper floor? The studio is going below my family room and kitchen and i am building independent walls and ceiling with 2 layers of 5/8'' gyp board with green glue. Also i already beefed up the cieling joist with 2 layers of 5/8'' gyp with green glue and caulk w/backer rod. I dont have any drawing i am building from Johns small syudio in 3d that is posted on front page . Thanks

This is an old post and I don't see an answer but what did you end up doing?