I KNOW this is the Bionic forum but the question was asked. FWIW, I'm forsaking the Bionic in favor of the Samsung Galaxy S II (Function on Verizon). And before I get flame-sprayed by the Bionic fans, let me preface this by saying they're BOTH gonna be kick-a$$ phones with great specs and a quantum leap upward from our beloved Droids.
That said, it all comes down to a matter of 2 words:
Unlocked bootloader.
Having been rooted & ROMmed for 19 of 20 months of Droid ownership, I have grown to rely heavily on nandroid backups. Anyone who follows my postings knows I preach them. Backups have saved my proverbial butt more than once. I want a phone I can root and backup - pretty much out of the box - without waiting on the manufacturer to come through with a "promise" to unlock the bootloader sometime near the end of the year.
Will the Bionic be a great phone? You bet it will... and I wish you guys well on your new purchase, since it looks like you'll be getting the Bionic before I get the Function. If the benefits of rooting (like backups) aren't important to you, the Bionic will serve your needs well for a long time. And maybe Moto WILL actually unlock it. Better for you!
But all said, all researched, all things considered... the SGS2 is THE phone for ME to get (considering it sold 3 Million units in 55 days worldwide and they even sent one to CyanogenMod for development) and THAT'S the phone I'm getting. My 0.02
I agree to people that dont care about messing around with their phones both of these will be great phones and it just depends on whether you want to wait or not. I think if you dont care about rooting the bionic is the way to go. It will be 4g(which function is looking like it wont) and if rumors are true even if the bootloader is locked it is supposed to get an update and unlocked like the atrix. Hopefully they dont water down the function like they did with the fascinate because otherwise it will be a huge seller for verizon maybe not as much as the iphone but a huge seller none the less. No need to flame anyone you make a great point people should go out and decide which one they like better and get that one no matter what anyone else says. Although as more and more apps and cloud services come about how do you know that you wont be able to do that without root? Not saying it will happen but it's not out of the picture by any means at the rate things are moving.
) and THAT'S the phone I'm getting. My 0.02


Data SHOULD be unlimited. Just like text messaging always should have been. Honestly consumers are totally shafted on text messaging every month, but nobody bats an eye. Any idea how much data a text message actually uses? yea...