Yeah I actually realized that I should probably grab some back-up sights for that optic, the battery life isn't great and I've had it die at a few games. Ordered some DE Magpul MBUS, as well as a Magpul MSA and MS3 sling.
I'll finally have a sling system that allows me to stow my rifle on my back while using my pistol or going hands on for various MilSim scenarios.
I think my next major upgrade to the externals will be this:
http://shop.ehobbyasia.com/accessori...etal-body.html
It was originally an SRC M4 RIS Gen III, so it's already shooting 400 FPS with .20's and has fairly good quality internals. Won't be upgrading those till something breaks, but I have a 11.1v LiPo on the way for it as well since the nun-chuck battery it came with obviously won't fit in the buffer tube.