For DC connections, easy to use. Perhaps would pause if using in high amperage/high voltage, but use them for landscape light wiring, 3d printer heater cartidge, misc connections <5amp <30VDC. Beats soldering and heatshinking with an iron.
Pros
The connectors come in a convenient storage case that keeps them organized and easy to find
Cons
The connectors may not be able to withstand high levels of vibration.