I experienced group boarding last week ex-Japan. To be honest, except for the signs with numbers at the front, I noticed virtually no difference.

Our flight was slightly delayed boarding so everyone was already at the gate. And this being Japan, things were fairly orderly to begin with (that being said, I've always found CX boarding at both HND and NRT among the more aggravating CX outstation boarding experiences (plus SFO), I think it just has to do with gate design).