Some might like the built in PSU, but personally, not a fan.
The PSU is one of the things that stops working more often than other parts of the PC, so having it external to easily replace it seems like a better move (also USB-C charging is nice, though it seems that this one doesn't have that).
So the is a slightly lower power, slightly lower spec'd, slightly cheaper version of the SER6?
It still seems like a pretty good deal.
Kinda sad about the internal power supply; but some users would prefer that, so more options are good.