For identical absolute max current and voltage ratings, which one is more reliable, IGBT or MOSFET?
For 600v, 20A for example, MOSFET is significantly cheaper than IGBT. I'm not sure if it is by chance, but if mosfet is truly cheaper for similar thermal and electrical characteristics, then is there any reason to NOT choose MOSFET over IGBT ?

 

Here you go!

 

That's a good paper, but it's a while since IR became Infineon, so it's not new. The argument hasn't changed, but manufacturers are regularly adding better high-voltage MOSFETs and faster IGBTs, so the boundaries are getting rather less distinct.
The 250V boundary above which one would never use an IGBT hasn't changed, but there are now some lower voltage GaN devices to add to the mix. Then, for high voltage there's Silicon Carbide and high-voltage GaN.