Both of my DDs are at Chellaston Academy, I went there in the 90s.
Its a huge school now and catchment is ridiculous. If you want to be guaranteed a place at Chellaston, you need to look at old Chellaston, Aston, Weston, Melbourne, Barrow on Trent or Ticknall - anywhere else and you'll likely be directed to Noel Baker or Merrill Academy. Even the Fellowlands way and Bonnie Prince estates in Chellaston, are not guaranteed places at the local school.
Chellaston has its issues, they had a teacher arrested and charged for grooming and underage sex last year, bullying is rife and they change the uniform policies almost daily it seems.
It used to be a great school, but as its got bigger and become an academy, it isn't what it used to be.
They do try hard I think, sometimes too hard, and they have the potential to be excellent again with their newly appointed head teacher.
I would choose Chellaston over Merrill and Noel Baker, but potentially not over Littleover, which remains an excellent school.