Static field is an amazingly underused skill in pvp. However, unlike pvm it doesn't bring their life to, at best, 1/3 or 1/2 (not sure how this works in pvm exactly), but it seems like it brings em down to 2/3 life all the time in my experience. However, I don't think it will work with most light sorcs. It works for me because I have hella -res (nova sorc). At level 1 with not that many +skill things (I use mana/life scs as opposed to light lifers), it extends a little bit further than the edges of my screen.
As to your question of whether to max it, thats a definate no. Its a 1 point wonder skill, theres no need for more. It doesn't reach more damage, just gets higher range, which I'm pretty sure has diminishing returns at high levels.
I usually use it against some of the more difficult bvcs who don't use bows. Stay away, sometimes cast a lightning or a few cbs at them, then static them while they try whirlwinding / teleporting up to me.