I've had the Verizon Wireless BroadbandAccess service several weeks now, and I'm increasingly pleased with the performance of the system.
I'd been having problems with Internet Explorer 7 (running on Microsoft Windows Vista Home Premium) that, at first, seemed exacerbated by the use of the PC5750 air card. After getting "on the air", I was having problems either opening IE7 at all, or after getting an instance up and running, subsequent use of that instance or starting additional instances would fail to completely open. The process would be started (as evidenced in Task Manager), but the window would fail to open. I noticed that during shutdown, all the windows would open (just before they closed to perform the shutdown). That led me to believe that some process was interfering with the initialization process for IE7.
After some detective work (okay, it was really "easter egging" -- getting into a situation where the problem was occurring, then terminating processes one by one until the problem cleared up), I was able to determine that Google Desktop was the culprit. For some reason, the unconfigured Google Desktop was intermittently interfering with IE7. To properly configure Google Desktop, I had to uninstall it, then reinstall and configure. I got the impression that there were still a few issues that had to be worked out between Google and Microsoft Windows Vista.
Anyway, everything seems to be working okay.