I think the allure of the cheap gun is like buying a used car in high school and kitting it out to be unique, and everyone knows that nice wheels make it go faster, right? The Impacts come performing at a level that other than basic tuning, any tinkering I do will just make it shoot worse. Cheap guns are different.
My Marauder was great before I started tinkering, but I had goals and wanted to make the gun "Better" by my definition. That meant higher shot count and shooting accurately out to around 50 yards. I built the gun to do just that. It's now nicely accurate at 50 yards, and shot count went from 32 to 55 shots per fill. I learned about regulators, hammer springs, hammer weights, and more building it.
I was actually disappointed when I got the gun to a point where I considered the gun "Done". That's kinda why I'm considering an Avenger. It already has all the things I want, but I can tune it to either be a sub-12 foot pound or a high powered slug gun. At $300 I can afford to dedicate the gun to either. Perfect for tinkering. And if I totally screw it up, I'm not nearly as afraid to dig into the gun as I am the $2000 gun (Yes, I have completely rebuilt my original Impact, even the regulator, and no, I don't recommend that).