Obviously the expedition broadly is both A) a really interesting story and B) is kind of problematic from a historical perspective as I understand it, but is the actual raft that Heyerdahl and his colleagues used a reasonably good reconstruction of the kind of raft they were trying to recreate?
It's outside my speciality, though it collides with it at an odd angle, but I feel it might be worth pointing out for anyone who knows of Thor Heyerdahl and the Kon Tiki, that the vessel is not a reconstruction of any vessel used in Oceania and is definitely not Polynesian.
Heyerdahl was basing his construction off of basal wood craft used for fishing and coastal cruising along South America. I am not an expert in Andean or Northwestern South American boat construction, so possibly someone else could comment on its authenticity to that tradition.
I don't have a lot of very specific details, but my undergrad archaeology professor rolled his eyes very, very hard at the whole concept of all of Thor Heyerdahl's work. And that guy was an archaeology professor specializing in the Vikings (another sea-faring people), so presumably, no, the actual raft Heyerdahl constructed was not up to snuff archaeologically speaking. Either that or the whole thing was so archaeologically awful that it didn't matter whether the boat was any good.