The best thing you can do on a Street Slide is go to 13" shocks to get the designed in cornering clearance back. Street Glides are lowered an inch in the back from the factory.
I added better shocks and front suspension too (see signature). I really like the feel of the 18" front wheel and tire combination also.
I have the H-D forward foot-boards which add a little clearance too. At the point they drag I am cornering about as hard as I consider "safe".
I do not believe the True-Track will do much to benefit a newer bike that is in good condition.