A lower compression is not necessarily "better" for turbo applications. A higher compression engine will make more power, howerver it is more difficult to tune.
For example, if you had a 11:1 engine running 5lbs, you could make say 300hp. If you had a 8.5:1 engine you could run 15lbs and make 300hp. However, it is much more difficult to tune 5-6 psi than it is to tune 15-20psi.