A grip is definitely not "essential" since you don't need it to operate your camera. I use one and it helps me when I need to take shots in portrait orientation, make it more comfortable when I do portrait shoots.
yes.. for a portrait shooter or someone who shoots lots of verticals.. no battery grip is kind of a sickening thing. I've became so used to the battery grip (I really shoot lots of verticals), and now I'm feeling weird without one. :cry:
I like batt grip kinda give me a better balance when holding the cam. During my film days have
fashioned a 'grip' for my film cam Contax RTSIII as it has a build in film winder. During those days
it's motordrives that serves as 'grips' asked any film veterans they'll know.