Coming from an iPhone 5S, and currently using a Nexus 5 I can say from experience that no email app comes close to the stock iphone mail app, especially when it comes to multiple email accounts, with push notification, all in one app that looks polished.
Yeah the stock email app is not very good - but the Samsung/TouchWiz one that ships with their 4.3 phones is decent - supports multiple/combined mailboxes with push and works reliably.
Android OEMs get a lot of flak for their skinning and feature bloat - in most cases fairly - but some things are just much better on the OEM skins.