Wow! I've crashed Pit-eck. They were cheap and crashed like it. Higher end body work as stated holds up much better. Think of cheap stuff as potato chips, when they break, they kind of shatter. Instead of fixing an hole thats ground through, your laying layers of fabric and resin to get it to hold it's shape again. It's very hard to get a good bond to an original section when your laying layers on top of something that was made as one piece. So the next time you crash, your layer separates and you have new damage. Instead of fixing a spot for the new crash, you fix the new spot, the old spot, and everything in between. With good bodywork like Armour Bodies, your repairs are typically located at the area of impact or abrasion.
As for fit. The better bodywork is always much better. Many of the cheap sets are sold cheap becuase they cut corners and costs. Things like curing time, weather, humidity, resin mix and a million other factors all affect how the body work comes out of the mold. Cheaper brands don't spend the time and research to ensure their resins are working optimally. Lower end bodywork is typically made from copying better bodywork. Instead of making their own molds, they take bodywork and build their molds from that set. Now..... Knowing that. Have you ever played the game telephone? You tell someone, they tell someone, who tells someone else, etc. The message you get from the 6th person is never the same as what was told to person 1. Imagine how that method works in manufacturing now. The mounting tabs are close. Some times, not even close.
Then you can get into finish quality and resin release, mold prep etc. I agree. You get what you pay for. Armour Bodies FTW!