Technically, setting the stripe by the soft rubber rollers is smarter (durometer changes), but realistically, who wants to pop rollers out of the press so as to see the stripe on some of the inner forms. I guess most would just read the stripe off the plate.
Also, very vital to get the press up to temperature before you start checking stripes (makes a huge difference). If the press is cold, we let it run in at least 10 minutes before checking. Usually though, I have found the best way to check forms is during plate changes - quick drop of the forms, roll the press, forms off and see what is happeneing under RUNNING conditions.
Also, put the impression on before the forms (creates considerable 'rocking' of the stripe). Roll the press, form of roll the press a little more, impression off. Using this method, I have seen (on a MAN Lithoman) a difference of up to 2 mm in stripe thickness from my water form. And since the press is running with impression on...well, seems like a good system to me.