I've had a look at the character sheet for Only War, and in putting together a character it seemed a bit limited.
Firstly, there were no spaces to list Aptitudes; I ended up listing them in the Psychic Powers slots, which isn't ideal.
Secondly, not much space for information about your Comrade.
Lastly, the space to put in gear seems a bit restricted, and it might be a good idea to print on the sheet the standard guardsman's gear that everyone gets, to save space.
Just some thoughts!