I am using mine (Nokia 6230) with my Z over Bluetooth, mainly for the GPRS. I haven't had time to experiment with OBEX, but ultimately I'd like to get the KO/PI suite syncing phone #s with the phone as soon as that code is a little more stable.
Setting up the GPRS was extremely easy, I would recommend caution for anyone thinking of using the 6230 for GPRS-over-Bluetooth, as it seems to have some sort of serious hardware flaw. It can maintain a GPRS connection for low-bandwidth browsing like WAP, but the higher-throughput rates of real browsing & downloading appear to blow out the phone's UART in some sort of nasty way, which causes the phone to reboot itself, or sometimes just drop the GPRS connection.
A little Google searching suggests that this is a known problem, but Nokia USA level 2 data support swears up and down that it's the first they've heard of it from anybody. (Their first line of email support also claims that they "do not support connectivity through third party devices", which is somewhere between highly misleading and patently false given the language they use to market the phone.) So I'm about to send in the phone to the service center for maintenance -- we'll see how that goes.
Otherwise I think it's an excellent little phone, although the plastic screen is kind of cheap and scratches easily/instantly. It boots really quickly (and because of the above problem I see it reboot quite a bit). I looked at the 6600 and went for the smaller form factor of the 6230 since to me the whole point of Bluetooth -- especially if you're a Z owner -- is that you don't need all that PDA functionality, or the screen real estate on your phone, because all of your browsing and PDA functionality can be done directly on your Z. Between a BT headset (for voice calls) and the Z over GPRS (for browsing) why ever take the phone out of your pocket?
I was hoping to get a simple Bluetooth phone without silly complications like a camera, but pretty soon it seems it will be impossible to buy one. It's hard enough to find a small BT phone that isn't a full-blown "Smartphone"/PDA-style device, since cordless syncing to a laptop/desktop, and wireless headsets, is all marketers seem to think BT is good for.
