Roger Shawyer (SPR), the Chinese (NWPU) and NASA EW have all measured thrust with EM Drive test devices and have theories of why the thrust is generated. Please indicate your belief as below
1) There is no propellantless thrust. Either the measurements are in error or there is some form of propellant creating the thrust.
2) There is propellantless thrust but the current theories provided by the experimenters can not be correct.
3) There is propellantless thrust. I have my own theory to explain the thrust.
4) There is propellantless thrust and the current theories provided by the experimenters explains why it exists. No new physics is necessary.
5) I have no opinion but will watch developments.
6) The measured propellantless thrust may be real. Theory options 2, 3 & 4 may or may not be correct.