Questions like yours are very hard to answer. If you plugged into a vintage Hiwatt, and then into a Ceriatone clone, you might prefer the Ceriatone. That is assuming it was a blind test, so that you could not see any logos, or have any way to tell what amp you were playing.
Ceriatone build quality is as good as anybody. Reeves has made a very good reproduction of the original Hiwatts, with a lot of effort in matching Transformer specs, and other things of that nature. If you want "The Best" Hiwatt in a new amp, I would buy a Reeves. If you are a gigging musician that needs/wants an amp that sounds/behaves like a Hiwatt, you will be happy with a Ceriatone.
Have you played many Hiwatts? Do you already have expectations of what these amps should sound/feel like? How important is it to you to have an amp that is "exactly" like a Hiwatt.
The Ceriatone will be very close. I imagine the Reeves will be  a bit closer to the "real thing", but you might not even notice. Perhaps some of the guys that own both can give you a better perspective. Can you build and solder?  A LOT of guys buy the Ceriatone chassis that is complete, with the exception of the transformers. Sourcing an original spec output transformer can go a long way in making your Ceriatone a "real" Hiwatt. Then again, you might not hear/feel the difference.
Good Luck