I use Emoze Push client on my Android device which gives the ability to push any type of email ,obviously Exchange ,IMAP,Gmail Hotmail but even POP3 which is very limited email protocol.
I've done benchmarks with the stock ICS email client and with several third party clients and I find that Emoze has the advantage in almost every aspect.
Push notification is stable and fast ,less than 60 sec.
Battery consumption is low ,I’m able to work in push mode without charging for at least 22 hours.
I’m quite a heavy email user so it was kind of a surprise to me because I used to have 6-8 hours max with only one account working in push.
I have 5 email accounts which is about 100-200 email per day so no kidding ,this one really improved my life ,I’m less paranoid about my battery.
Other features which are quite useful are the security options that allows you to find the device location by SMS or email and also to remote wipe or block by SMS.
This is cool because you don’t need PC connected to the internet to get the job done ,you can simply send SMS to your phone number to activate the security process.