Guess it depends on the pedigree you are considering.
Porsche's Mezger Engine (GT1 Block) is probably the most successful race engine of the modern era. It was born and bred a motorsport engine and used in street cars for homologation rules. This engine has been in every GT3 / GT2 and Turbo produced since 1999 with it's run officially ending in 2012...though it was still used in the Porsche factory race cars through the end of 2013.
In the GT3 variants the differences between race engine and street engine were minimal with the street engine retaining even titanium connecting rods from the race engine along with a true dry sump oiling system. Power levels in the street cars were only down 5-10% from the race engines with the main differences being camshafts and a slight variation in the heads to optimize flow.
In street form this engine first showed up in the 1999 GT3 in Europe producing 360hp out of a 3.6L engine that would rev to 8000rpm.
It's last iteration in a street car the motor had grown to 4.0L, produced 500hp and would rev to 8600rpm.
Because it was developed as a race motor it has proven to be extremely robust as a street motor. You won't see Mezger turbo motors as serious drag racers however there are several tuners out there making good, reliable power with them just not on the level of some of the other platforms for drag racing