The NeoSD I think is pretty decent from the reviews I saw. And $500.00 is a steep price, but well worth it considering most game on the AES worth playing go for $250+.
If Krikzz were to develop a Neo AES Flashcart could he do it without the 2-6 minute load times to boot the games? I thought there was no other way around it since the AES uses Flash RAM?
Anyway, I think Krikzz should try his luck with a SegaCD-SD. Not to say he can't do a Dreamcast-SD or Saturn-SD, but the Rhea and GDEMU are already up and running and have most of the market.
EDIT: If Krikzz is going to get into the Saturn, I think he should try to partner with Professor Abrasive and make those things (believe they are going to be called Saturn Satiator). Sort of like he did with Ikari and the SD2SNES?