Hmmm, after getting blasted on on the "call to action" thread because "everyone" is having problems, I do see some successes here.
I am posting from my tethered BB 8830 right now which took about 5 minutes to set up.
A point here that everyone seems to have skipped is that this is potentially a carrier issue. I suggest a poll of what carriers are having problems and which are not. I am on Sprint, no problems.
Another point is the configuration being used. Remember, despite the fact that the carriers do sell you an unlimited data plan it does not mean they want you to use it that way. Many have different AP's depending on the device and I know for a fact that ATT/Cingular does throttle your connection speed depending on which AP you are going through.
Lastly, depending on the device, you may or may not have high speed access. Most EVDO phones are not Rev A. So if you compare the speed of a dedicated EVDO modem to that of an EVDO phone on the same network the speeds will not be the same.
And to those that accused me of trolling, look at my post history - I don't troll.
You're not a troll?
The problem that we are trying to resolve is with the Bluetooth hardware on the MBA. We are having latency and speed issues when we are tethering our phones over BT. You did not clearly indicate how you are tethering your MBA to your BB, which could explain why you may not be having related issues.
Unfortunately the problem is definitely not the provider and not the phone (WM6 HSDPA phone capable of 1.8mbps down/384kbps up).
We do not have any problems when we are using alternative means to tether our phones. For example, on my Air,
1. Over Wifi using WMWifiRouter (software), or
2. Using a USB cable and Internet Sharing (software) through Windows XP (virtualized)
brings about no latency or speed issues.
To confirm that BT on my phone is not the issue I have used a Windows XP laptop with Bluetooth V2.0 and also had no issues. Slightly slower in speed than over Wifi but similar latency values. Additionally, dyerucf has reported no problems with his MBP.
Therefore the problem seems to be narrowed down to a software or hardware issue with the BT on the MBA.