Thank you all very much. This is exactly what I wanted to know!
The other thing I meant to ask is that I have been told by a work colleague who has an older model of BB (the 6280 I think) that when he is on a call and a new email or calendar entry arrives, his phone conversation drops out temporarily and then returns..! He says it's really distracting and annoying, and as such he now carries two devices - his old Nokia phone for phone calls, and his BB for email and calendar, etc.
I definitely do not want to carry two devices, so I was wondering if this problem is known, but has been solved in newer versions of the software? Or if it was related to specific handsets, etc?
Thanks again for everyone's speedy answers! I'm sure i'll be a frequent visitor to this site once I buy my 8700g.