Phil from Android Central put the brand new (and currently pulled for bug fixes) Gmail for iPhone and iPad app on an iPhone 4 and iPad 2 running iOS 5 against the Gmail app on a Samsung Nexus S running Gingerbread and a Galaxy Tab 10.1 running Honeycomb.
It's easy to see Google took the easy way out with Gmail for iOS, going for a tragically thin native wrapper around the similar-old web content. Maybe they're still limited by the iOS SDK, maybe they want to keep Android as the premiere Gmail experience (and who could blame them?), maybe it's a hormone thing, or maybe they just want to prove Facebook isn't the only rich, powerful web company that can't release a stable iOS app, who knows?
Hopefully Google takes this as an opportunity to learn and gives their massive iPhone and iPad wielding user base a new Gmail app worthy of the name. And of Google.
Source: Android Central