verdict: forget about it when running cpu hungry audio apps.
It emulates only a G3, so all the altivec SIMD acceleration is not available.
For office-like apps and non real-time apps it's ok but if you
buy an Intel Mac you will have to hope/wait that your favorite audio app vendor ports their app to Intel Mac.
Or alternatively recompile the LinuxSampler source code on your shiny new x86 Mac