can i be the first to point out that Rob had 0.5psi more of boost too, it would make a bit of a difference.
higher compression always gives more power over a low compression engine, it's just a case of the componants taking the strain, which is why the economic costing goes towards lower compresion for more room for error and reduced strain.
in an ideal world we'd want really high compression to get more power out, but the costs of this can rise substantially.
another example is that i had a leanburn non turbo 1600cvh with a 0.5mm over bore running 13psi of boost and that was pulling just under 200bhp (197fwhp IIRC), same setup but with standard rst pistons didn't pull anywhere near the same power (wish i'd have a RR session on it to see the difference)
there are articles all over the internet where this is discussed in more depth.