i know of you from another forum so you should already know the answer since you have the answers on everything else
but for those interested it's all about power/det, basically a lower compression ratio engine can run more boost and advance to get a certain amount of power out, the same power can be achieved with less boost in a higher compression ratio engine but the tolerances are so much tighter for ignition and timing, so lower comp is favoured.
if you want big power and don't mind pushing as hard as possible to achieve this including loads of time mapping getting every last bhp out of an engine, then high cr is the way to go.
also materials made for engine componants and cooling play a big part too.
that's it in a nutshell, there are lots of factors though that do finally decide the cr targetted.