Having departed from Terminal A for the second time since it opened as my origin airport I have learned from the first time that Clear is NOT the way to go.
Got to EWR about 6pm on a Sunday and the TSA PreCheck line was empty while there was a medium-sized queue for Clear with none of the machines on because all of the Clear Ambassadors were escorting other people to the BP checker. TSA PreCheck, meanwhile, you could "walk right up", they scan your ID and you're in. After having sat in the silly Clear line the first time through Terminal A I remembered...never again.
I don't know if it's because they just don't have enough Ambassadors for Clear or because the security layout is absurdly dumb on a brand new terminal. Either way, if you want to waste your time just to scan your eyes/fingers feel free to stand in the Clear line.
When I looked back at the Clear line after my bags came off the security belt I would say maybe 3 people had gotten through, if that. And the line was longer. At that point Clear should just shut down and tell everybody to go to the regular TSA PreCheck line.
-RM