Seasoned versus New Aftermarket blocks?

It has always been tradition, to try to build a high performance engine from a used, seasoned block that is inspected and known to be good.

Now, with the advent of the Motown block and the Dart Little M block on the scene, how will that affect this thinking?

Is it risky to build a $10K motor using a brand new, never run block? I know some guys are doing it. But what will the long term result be?

Is the metallurgy, casting, and machining processes today resulting in a worry free situation with a new block for high performance use?

If these guys know what their doing with their casting processes (with regards to cooling rates, post-casting heat cycling, etc.), then I would say that there will be no problem with using a brand-new block for a high-perf application. After all, high-perf cars use brand-new blocks from the factory, right? ;)

Interestingly enough, BMW scoured the junkyards for 100K+ blocks for their F1 motors back in the 80s (this 1500 HP monster was based off their production four-cylinder - take that, Supra fans :p). Obviously, they saw value to using a seasoned block, but that was over 20 years ago.