First off, you should pick a device that fits YOUR NEEDS, not the opinion of the public.
Secondly, if you decide to stick with that trusty blackberry, you may want to consider a BT headset. The Plantronics Voyager 510 has nice noise cancellation features. It can also connect to two different BT phones at once (you can answer a call on either, but not at the same time. It saves time from having to switch the connection from one phone to another)
Keep in mind that MOST PDA's are going to have a little poorer voice quality (from what I have found and experienced) than your regular phones. I suppose the idea is because they were designed for corporate environments.