I'm not an Apple fan at all, however, any device, whether it be Apple, Blackberry or Android can work fine in the business space. That being said, the Apple and Android devices will have some challenges due to the inherit design of their O/S. (Note: I do have a role in the mobility space for my company, we have about 15,000 mobile devices connected to our network).
Blackberries are built with the business user in mind. The new devices actually come with 2 separate profiles, one for your business needs and one for your personal needs. The two profiles are completely compartmentalized, which means both your personal and business data are completely secure. This provides you with far more flexibility and information security in the corporate space. This is all controlled through Blackberries BES 10 server and is all native to Blackberry. To be honest, in the majority of cases for the business user (both for BYOD and corporate owned devices) the Blackberry will provide far superior functionality and security due to the built in features of this device.
Both Apple and Android are more for personal usage and neither have a native Mobile Device Management solution. What that means is there is no means (naively) to separate your corporate data from your personal data. Both need to have a 3rd party MDM solution to connect to your work email. You are victim of that solution as not all will have the functions that you are looking for. Most will even you to install a 3rd party app to access your mail and have a second app just so you can view any attachments. Both Android and Apple have this exact same problem as they do not have a corporate solution.
I hope this helps!