When you jailbreak the iPhone you pretty much give yourself r00t access and the ability to run unlicensed code.

You can theoretically play with the kernel, drivers and bootloader but that's hardly targetted.

The normal iPhone can't use the BlueTooth for many functions and devices, its basically like having no bluetooth. A jailbroken iPhone lets you have full control over its BlueTooth module, in fact pretty much everything... it becomes N900-like.

I don't have a jailbroken iDevice, but I'm basing this off from internet research and a co-worker who has an iPhone 4 jailbroken (and refuses to update). We sometimes do "competitions" with my N900... but lately I've been getting the more praises with my "hacked" Note.

About the hwkbd issue... I think if you auto-paired the accessory to the iPhone, then ran a script that would turn the BT on when you slid the keyboard open (gyro sensor, nfc/magnetometre, camera sensor). And actuated to turn the BT off with a shortcut on the keyboard (like Fn+Enter). Then problem solved. The accessory will last a long time without charge, but the iPhone battery life is the real issue here. Doing some solution like that ensures the BT can quickly turn on and pair then be easily turned off... limiting the footprint of its power drain.

I mean if Apple sells an iPhone with a 4in screen, a slide out qwerty, microUSB port... most complaints in this comparison would've been attenuated. A jailbroken "iPhone PRO" could really give the N900 a fight for its title.

...but why are we discussing jailbroken iPhones anyway? Wouldn't it make more sense to get an Android device that can be hacked and give you some of those functions.... Hell they even have dualboot native Ubuntu options for a few!