[General Questions and Answers] phoare:
Partial answers:

1) As noted above, many companies have spent large sums of money on their BB infrastructure so aren't about to throw that away. There's also, in my opinion, a perception that BB devices are "for email" whereas MS devices are phones. Hence conservative big business goes for email devices rather than phones.

2) Personally I don't believe BB has any real advantage, but some people would disagree. Some like the BB devices more than the phones. Certainly from an IT and cost perspective, setting up a BB infrastructure is not for the feint hearted.

3) There's a huge amount of misconception about the traffic that DirectPush generates - it need be nothing like what many people make out (certainly nothing like the 400 bytes every 2 mins quoted above) but it does depend on - primarily - your firewall settings and how swiftly your firewall terminates the HTTP(S) connection.

5) Ensure you have good anti-spam software so that you're not getting spam pushed to your phone! Set it up so that only the first few K of any email is sent by default - you can always request the entire email if it's necessary. If you have access to WiFi periodically, then sync your mail then - that way, when you get a new email, it won't trigger a large sync. Likewise, if you're only using DirectPush occasionally then keep your Inbox lean - don't store loads of emails in your Inbox as those will get sync'ed down.

6) Umm... if you're connected to Exchange via Outlook on your desktop, then wire your phone via ActiveSync and you won't need DirectPush on... and then your phone will be fully sync'ed as soon as you unplug and go on the road.

7) <rant> Forget the moaners who tell you that DirectPush is not true push as there's a 'ping' sent from the phone. That's irrelevant - who cares!! When an email is received in Exchange, it's pushed to the phone. That's all that matters!</rant>

9) I don't believe that DirectPush is slower. There are many other factors that may affect the timescale by which an email is sent to either an MS or BB device and those factors are much more likely to have an impact on the timeliness than DirectPush itself.

10) Never had any problems with DirectPush myself.

16) It is the firewall settings as you describe that are key. But how are you deciding that you're using that number of Mb? Data traffic is charged by some operators in blocks, and hence a small 'ping' could be costing you one block even if it's only a fraction of a block. Also, some traffic monitors can be configured to count in blocks. So my first suggestion (if you haven't already) is to double-check that this 1.9Mb is what you are actually using, not simply whatever some piece of software is incorrectly reporting. Next up, how many K of each email have you set it to download per message? Secondly, remember that it's doing a sync when a new message arrives. So, if you're in Outlook on the desktop, and you get 10 messages which you leave in your Inbox, then you put DirectPush on, then you get 1 message, you'll be sync'ing 11 messages. I can be a relatively heavy user of DirectPush on any one day and still use nothing like 1.9Mb.

Hope this helps.