Though I have only got the $450 clone, but I can tell how good of a design this shotgun is. I have shot 1500 rounds with the clone and I done extensive polishing to my m4 clone and examine the parts many times. I would get the benelli one if my clone is broken somehow. here is a list of good designs of the m4.
1. it being gas driven with a regulator, you can tune all the springs to your loads, it would cycle the lightest/heaviest of load with a simple spring change. though original spring would run everything.
2. the receiver is never under any stress, all excess recoil energy directly goes into the stock tube and into your shoulder. unlike other mag tube spring designs.
3. the gas system is a breeze to clean, basically 2 smooth bore pistol barrel, not that you need to clean it at all, piston basically scrape extra carbon off and dump it into the handguard.
4. feed system is flexible, and no way to cause a jam. unlike a lot of the hunting gun designs.
5. no plastic internal parts, yea perhaps it make the gun lighter. but you never hear m4 parts breaking.