Things of note:

• The prototype is clearly not stealthy, as the air data probes appear to my untrained eye to be retroreflectors.
• The control surfaces on the leading edge of the inlets are pretty big.
• The all flying tails are very obvious.
• Visibility out of the cockpit is not quite as good as the F-22, but roughly equivalent to the F-35.
• Russians hug a lot more than Americans (2^nd vid)

H/t The DEW Line