1. Big blocks are heavy and lightening the front end to make the car more nimble was certainly the main factor in choosing an aluminum block.
2. There was a certain symmetry with having an aluminum block in an aluminum body with a billet aluminum suspension and wheels and an alloy differential.
3. Back in 2008, there wasn't a shortage of aluminum blocks and, from memory, Genesis was one of the only producers of new iron FE blocks and they were having casting/porosity issues with their blocks at that time.
4. The price difference was relatively negligible. New FE blocks were roughly $3,500-$4,000. The Pond alloy block was $4,000-$4,500. And the Shelby alloy block $5,000-$5,500. I can't remember the figures exactly, but that's ball park.
5. The rumor mill or "I had heard" that the mating of alloy heads to the cast iron block caused metallurgical issues, which in turn caused sealing problems and
oil leaks. And most sports cars today have all alloy engines, so that was somewhat comforting at the time.
6. Bragging rights. Yes, we all have egos.
Would my decision be different today? Maybe, even probably, depending on various circumstances like shortages, block casting problems, etc. Today, I'd be more likely to choose a cast iron block than 8 years ago.