Make sure you try on the Kaijus, and that they fit your foot.
It may be the boot you really want, but if it doesn't fit your foot and you still go ahead and pull the trigger on them, and you have a shit time on the hill, don't come back bitching about how shitty Nikes are.
With that said, the Kaijus fit my foot really well, and I love them. Been on them for the past 3 years, and just got a pair of the Gold/Black Kaijus from this year.
I have the same ones. The Gold/Black Kaiju. Was tempted to get this years Black/Gold and wear one of each lol.
But you are absolutely right in your advice. He should definitely get sized up for them before buying them