A couple weeks ago we reported that Google said that all flavors of 30x redirects pass PageRank fully, there is no dilution he said. So of course, there was some debate on that but it seems like the way Gary Illyes put it, there are less people calling Google a liar for saying so.
Gary from Google also added on Twitter that while 30x redirects do not dilute PageRank, 301s help best with canonicalization.
Meaning, if you are trying to tell Google how they should combine URL A with URL B, use a 301, it helps best with the canonicalization of such a URL move.
Here is the tweets from Gary:
I wonder what will come out of Gary saying this.
Forum discussion at Twitter.