These reusable connectors have good springs on the levers which very positively grab and hold the inserted wire. The clamps release easily when the lever is lifted. The springs are strong enough that the clips will never open accidentally - you have to really pull on the levers to get them to release. Much better than vampire taps IMHO. The only con i can see is the overall size of the connector but that is the tradeoff for getting four high quality miniature spring clamps into the enclosure.