I started out with an Eastwood gun. It was ok but I powdercoat a batch once a week of around 20-50 pieces so semi production? I do over 1,000 pieces a year so my experience may not be applicable. But except for my gun all my stuff is semi home brew. My small powdercoat booth, my dust cyclone are homemade. My old home electric oven is one I got off CL for $25. Works excellent. All my stuff fits in the oven no problem with the homemade racks. So most of my rig is repurposed and DIY. All my material is new but I do have a small HF blast cab that I need to get back to for mod's so it would work better. But since I rarely need it, it's been sitting in storage for 8yrs.
The gun I have was $800 and was the best upgrade as far as finish because of my parts. Faraday effects odd shaped parts with lots of surfaces making no matter how much powder you blow in there not stick. The guns in this price range have circuitry to deal with this and it works good. I don't have bare spots anymore and finish is more consistent and smooth. But it's hard to justify this for home use but I just wanted to put out there that there is a difference.
Like paint, prep is paramount. So clean surface, as dustoil free as possible and a good dryer on your compressed air. A booth keeps dust and wind from fouling the part and keeps the powder from fouling the shop. My booth is 24"x24" open in front and top with a DIY vac setup and contains the powder amazingly good. It's on a stand made of conduit so it's at the right height and on castors to move around. I need to put a top on it to stop the last of the eddy currents of wind from messing with spray.