We flew Song for the first time 08/24 & 08/30 our of Newark; we used curb-side check-in as we always do, went through security & parked down at the gate for the long wait to board. The only difference from Delta Express is that they board by zone, not row numbers, and it seems somewhat disorganized. Hopefully with some more experience they'll get better.
Oh, and as a PS, my DD, 17, hated their "perky" flight attendents on our 7:00 am flight to MCO; she said it's just unnatural & obnoxious for anyone to be so "up" at that hour (and I pretty much agree with her, the in-flight talent gets a little lame after awhile)!!!