Windows mobile sync can also be secure, depends on the provider - the same as blackberry, it's no different. Windows mobile/outlook supports push mail the same as blackberry - there's no difference. In fact from a corporate point of view Exchange and Systems Centre Mobile Device Manager has some features that Blackberry can't compete with yet.
From a device point of view, and bearing in mind Tonio isn't connecting to a corporate push mail server, be it blackberry or windows based, the HTC HD is the hands down winner IMO. Most providers, apart from Orange it would seem, do an unlimited data plan fairly cheap which would be good for email and developing on the fly. Orange bundled data is not expensive but I wouldn't go calling it cheap yet.
Having said that, now that you've got a business Tonio it would be worht investigating what business tariffs you can get from various providers and this deal *may* sway your handset choice. If I was in your shoes though, I'd pick the HTC HD all day long.
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