As a user/consumer I consider the search or discovery of new apps on the MAS quite horrible, the features you mention are nice but IMHO they come "after you found the app".
IMHO an app dev is better off implementing the payment system and update than using MAS, for ex in my case there is no way I would wait 7 days to have an update out of the door (eg. I don't automate everything to get blocked on the last step).
IMHO an app dev is better off implementing the payment system and update than using MAS, for ex in my case there is no way I would wait 7 days to have an update out of the door (eg. I don't automate everything to get blocked on the last step).