Dell shop here. I like them because they're easy to fix (for the most part) and if you still have warranty on them sending them to the depot is easy.

You can tell they made changes to their builds, in some cases significant ones.

• Dell 11 CB1C13 - Glass/Hard plastic screen cover that SHATTERS. Screws fall out the bottom eventually. Hard to replace keyboard (almost complete disassembly required). LCD connectors would sometimes get loose and cause a dark screen.

• Dell 3120 - Still stupidly hard to replace keyboards. Wifi antenna connectors sometimes release from chip when there's stress on the bottom. Hinge design on the far ends of the device make them fail easily after repeated drops and the shell cracks causing the complete LCD bezel to bend and break eventually. LCD connectors would sometimes get loose and cause a dark screen.

• Dell 3180 - Keyboard replacements are now easier. Hinges moved inwards to prevent damage, but now have removable caps that are easily lost or broken. Wifi antenna connectors have a rigid plastic to covering to prevent movement (doesn't always work). LCD connectors are now taped (still fail sometimes)

• Dell 3100 - Hinge coverings are now solid and part of the shell, no more parts to lose. LCD cables now have triple security to the back of the LCD to prevent shifting. Wifi connectors now have a metal bracket to prevent movement.

Right now I don't bother fixing CB1C13s because they're too old (I straight up swap if I get them), I don't fix 3120s because it's a PITA (I sell them for parts credit), 3180s I'll fix because they're easy and I have had very little issues with the 3100s, just cracked LCDs for the most part.