Because of clearance issues, i ended up having to go with a 3/8" material for a couple rooms of my house. This was a nail down install using a 18g bostich nailer and 1.25" cleats.

The issue I had was with the nailer causing the finished (top) edge of the board to chip / splinter a hand full of times. Especially now that I'm done with the rooms, i'm finding more and more spots where this happened. Visually they dont stand out, but you can definitely feel them as you're walking across the floor. Out of about 350sqft, i've probably found a dozen spots where this happened. I'm thinking a light spot sanding a some touch up with poly will fix the spots, so it's not a huge concern. What i'm curious is if this is a common issue with 3/8, or if I just did something wrong? Maybe I should have dialed down the PSI on my nailer?

Yeah the bumps can usually be seen in reflective lighting and felt under foot. Didn't sink the staple enough.

An oak floor? Does it have the micro bevel? Square edge is more prone to chipping or splintering. It takes practice to work the nailer just right.
Touch up the areas without sanding them, unless you are going to coat the whole room after touch-up.