We have purchased Dell kit for over 12 years, recently 150 7480s and frankly the build quality and design is shocking. Firmware issues, batteries expanding, spring clip RJ45 port which can break easily, motherboards cracking due to the flimsy case, support issues, etc. has lead us to look at the Lenovo T470s range. We stopped buying their servers as well.
Three different account managers in 1 year and no reply from our global account director for over 1.5 years. They can't even change our billing address for our NYC office even though we moved 4 years ago.
At least their monitors are still great :) 34 inch ultra wides have proved very reliable and the screen quality is flawless. Then again they don't make the panel!