I will just quote a post from Secretprojectsforum (https://www.secretprojects.co.uk/threads/turkish-tfx-national-combat-aircraft.13448/)
By "PringleiPrick"
"W.r.t. to calling the TF-X a stealthy F-15EX is selling it a bit short, in my opinion. I think you're right in terms of flight dynamics: similar thrust engines (Block 1), approx. same size, probably similar weight if we take into account TF-X' extensive use of composites. However, its tech will almost certainly exceed the F-15EX: built-in EOTS and IRST, DAS, larger GaN AESA, HMD only (no HUD, a la F-35)... At least, I hope it will."
By "PringleiPrick"
"W.r.t. to calling the TF-X a stealthy F-15EX is selling it a bit short, in my opinion. I think you're right in terms of flight dynamics: similar thrust engines (Block 1), approx. same size, probably similar weight if we take into account TF-X' extensive use of composites. However, its tech will almost certainly exceed the F-15EX: built-in EOTS and IRST, DAS, larger GaN AESA, HMD only (no HUD, a la F-35)... At least, I hope it will."