As we all now in case of CPTs WP stores all the custom fields in post_meta table, which works of course but is far from being ideal. To show render any custom data for the users WP needs to look through 2 tables or join them. Or if the admin adds later a new custom field to a CPT those land at the end of post_meta table making that whole table a complete mess of randomly mixed data. Even worse if one does not need a custom field in a CPT anymore, well then those data remain in post_meta as orphans.
IMHO instead of all the above each CPT should have its own table in the DB. Everything would be much better organized and more flexible that way (one could add or delete rows anytime to any CPT without leaving garbage in post_meta). Even queries would be faster. I do not see cons at the moment.