I prefer gridless, in general, in PBP...but it's not always feasible. In particular, if we as a party start using a lot of positioning tricks and tactics, we may eventually want or need a map, but for simple battles it speeds things up a lot for the GM not to rely on one.
I think as long as you're fairly generous about telling us about positional possibilities, like if we can flank or not, or where terrain features are, it'll be fine.
My only comment is that it was a little weird trying to figure out where the orcs were at first. It seemed like they ambushed us from a ways off, but then the folks rushing into melee were right on top of them...maybe in the initial post if you give a little breakdown like:
Orc 1: 30' away behind a boulder.
Orc 2: 25' away and 15' up on a cliffside throwing axes.
And so on. Just to give us a basic idea of how things stand without requiring a lot of overly-specific text in the description that might break up the narrative.
