1 Nickel

RE: Dell TB15 Desktop Dock - Step-by-step driver/firmware/BIOS installation instructions for XPS, Latitude and Precision notebooks

On the intermittent connectivity issues, please double check that all drivers, firmware and BIOS actually did update.   The easiest way to check driver version is from the desktop.   Right click on the start icon and then left click on Programs and and Features.   The driver version will be off the screen to the right but you can adjust column width to fit everything.   Compare this to the list posted in the first item in this thread to verify.   You can check BIOS version by running MSINFO32.

It's worth it to note that I had done this prior to uninstalling everything and then re-installing.  All driver numbers did match up properly.  All BIOS and firmware claimed they were up to date.

I can't be sure what fixed the majority of my problems, if it was the uninstall and re-install in a particular order or if it was re-running the thunderbolt firmware update with the /f switch or if it was even the clean install of the graphics drivers.  It's hard to say right now.

What would make me more confident in this thing long term would be improvements in two areas (beyond the hoop jumping you have to go through to get it installed and working properly), behavior after a reboot while docked and reduced chance of graphic corruption after plugging in.

Specifically, sometimes I lose all display if I reboot while docked and sometimes it behaves as normal with the login screen coming up on my primary monitor (often times when it blanks out after reboot, it briefly displays properly on the external monitor first.)

For the 2nd issue, it's the fact that there seems to only be a 65% success rate in having the internal display on the notebook working properly after plugging in the dock.  Sometimes when I plug in, the internal display of the notebook freezes after the external display lights up.  The external display functions fine and it THINKS it's part of a multi-display system (the both displays show up when you look at graphics properties) but the notebook display remains frozen until you undock and dock again.

If these two issues get knocked out with an update, I'll feel a lot better about this thing.