Wireless Broadband Newbie needing help.

[barrywohl]

I've been using ThinkPads since 1995, but the X230T I bought in August, 2012 is the first time I've had a wireless broadband card. I've always just used wifi before.

Device Manager tells me I've got an:
Sierra Wireless MC8355-Gobi(TM) 3000 HS-USB Modem 9013
I have an AT&T SIM card installed.

The laptop came with Windows 7 Pro x64 but I've never used that operating system. I just replaced the original hard drive with an SSD drive and loaded Windows 8 x64 Release Preview when the laptop arrived. This weekend I've changed over to Windows 8 Pro x64 RTM.

When I had the Windows 8 Release Preview, I worked with AT&T and with Lenovo EasyServ to get the WWAN card going, but I never succeeded, and rather than spin my wheels and supports' wheels on a beta operating system, I postponed this issue until the Windows 8 Pro public release. When I worked with Lenovo EasyServ and AT&T support I tried to use Access Connections, Mobile Broadband Connect, AT&T Mobile Broadband Manager, and I only succeeded in invalidating two or three SIM cards without ever getting it going.

I see that Lenovo no longer uses Access Connections for Windows 8. There's another Lenovo program, "Mobile Broadband Connect" that doesn't seem to be part of the Windows 8 suite either.

The Windows 8 Pro RTM didn't automatically find the correct driver for the Sierra Wireless card, so I ended up using the Lenovo driver file 8awt16ww.exe to get Device Manager to be happy with the card.

What steps do I take to get the Sierra Wireless WWAN card working under Windows 8 Pro?
Do I contract with Lenovo to buy air time or do I contract with AT&T to buy air time?

AT&T is my cellular phone provider for my business phone and my smart phone, but I think their "Mobile Share" is not as good a deal as the Lenovo - AT&T deal, since I will be only an occasional use of the Sierra Wireless card in the X230T.

I would appreciate any help I can get to steer me in the right direction to activate and test this device.