Pascal: Well, we introduced USB support in NI-VISA 3.0, which shipped with LabVIEW 7.0. It will also work with LabVIEW 6x, but it's the same NI-VISA driver. So it's not really a question of "which driver is better".
As far as known bugs, there are 2 that I'm aware of, and we've fixed them in a soon-to-be released NI-VISA 3.1. I don't have an exact date, but if you need more information, let me know. The bugs are: 1) The VI_EVENT_USB_INTR event attributes did not work properly. 2) If you unplugged a VISA USB device and plugged it back in, NI-VISA could not access the device properly. I hope this helps. Dan Mondrik National Instruments
