There is confusion over some other details as well... Yamaha's website touts an increase from 32 to 64 poly and an "Organ Flutes" (drawbars) feature. But these are not confirmed by the online specs nor the manual. Inquiring minds want to know!
One of the most important upgrades is an increase in style RAM. There are still only 2 variations per style, but the e413 was limited to 35KB, so even cut down styles from higher-end boards wouldn't play. I believe the new limit is supposed to be at least 50KB.
If Yamaha is serious about downloadable content, they are missing a marketing opportunity here. They should offer "lite" versions of their premium styles (2 variations, no MegaVoices, etc.) but lower priced like MP3s. It would get a lot of first-timers hooked on the idea of downloadable content for their keyboards and expand the board's appeal.
IMO, the PSR-e423 looks to be the best keyboard in the sub-$300 price range, as was the e413. -Ted