Thunderbolt Docking Experiences

I just wanted to see how other user's that use Thunderbolt docks have turned out across multiple hardware platforms. I have only limited experience in the Dell Thunderbolt docks and haven't found anything that works 'consistently'.

Is this pretty common across other user's experiences? I've known others who use similar docks without 'too many' issues. Most of these users have very low resolution monitors and I wonder if this is a root cause or if it has more to do with the Thunderbolt spec being implemented.

I've ran TB16/WD15 docks on my 5510 precision with a 4k display with a 4k Samsung monitor alone without too much display issue just some USB issues. I've also tried the TB16/WD15 on a 21:9 1080p monitor and a 1440p Dell monitor and don't have issue with the TB16, but the WD15 has various display issues. I have heard that the display issues have been related to the an 'under powered thunderbolt connection' and it requires an AC adapter to be also connected. This has upset me significantly because I feel like the dock fails to meet the specifications provided by the manufacturer. It does not provide appropriate power for the laptop to output a resolution that the dock is said to support.

I know I'm sort of ranting here, but I do wish to know if others are as frustrated by their Thunderbolt docking experiences as I am.