For my BIS email, I also use forwarding. Many different ISP's permit you to forward a copy of all your emails to the BlackBerry. So you get them normally but you also get a quick copy on your BlackBerry within a few seconds.

The 8700 is about the same speed as the other models - less than 5 seconds for receiving emails usually. (Assuming you are using forwarding instead of POP pull).

Be noted, that you can have better email reconcilation (deleted, read) when using T-Mobile BIS with POP pull. So in exchange for slower email reception, you get email reconcilation.

However, I prefer the forwarding method, even though I have to read each email twice -- once on my BlackBerry and again on my main account.

I also use BES too, but that's for my work emails now.