Disagree. The reason that Gmail for iOS and Gmail in general suck is the total lack of support for cryptography within the application (S/MIME, PGP, or other solutions).
As a friend of mine said, "Gmail -- a private conversation between you, me, and 25,000 SREs."
Better to say "between you, me, and the internet".
Remember that email is typically transmitted between servers in the clear, so it's trivially easy for your messages to be observed by arbitrary third parties.
As a friend of mine said, "Gmail -- a private conversation between you, me, and 25,000 SREs."