For a brush gun, I usually prefer open sights, but when I DO use optics for short range shooting, I'm starting to lean towards the Holosites (aka "open style red dots") instead of a tubular Red-Dot scope.
It's nice having the 3-4x magnification of a Red-dot scope, and I REALLY liked my Bushnell Trophy Multi-Reticle, but for "head-up" shooting in the brush, I'm really enjoying Holosites. Truglo is probably my favorite of the 3 I have.
Ideally, if money wasn't an issue, I'd have 3 or 4 more of the EOTech G23 sights (holosight with flip-to-the-side magnifier tube), but at $1000 a pop, I could only justify buying one!
Try out an "open-style" red dot and see how it works for you. Otherwise, it's hard to beat the Bushnell Trophy or Truglo Tubular Red-Dot scopes.