The TB15 had firmware (BIOS) AND driver updates on laptops (XPS13 / XPS15 in particular) as well as firmware and driver updates for the hub itself. They still couldn't get it right so must have been buggy hardware or chipset in the end.
I don't even have one but my XPS 13 occasionally pesters me about new firmware/drivers for the WD15 or TB15 (maybe both)....
I'd be very wary until it's been out for a while. USD300 ain't cheap either.
#40104192 120Gb (no longer in my E36 M3, won't fit the E46 M3)