Well I cannot say anything about those because I have never used them or a bucket period. I went to walmart and bought a 10 gallon rectangular tote for I think 4 bucks and then bought a 1/2 pvc valve for 5 bucks.
It really does not matter to much what you use as long as it is clean and fits your use. I brew 6 gallon batches so a 5 gallon bucket just would not work and I could not see paying 20 bucks for a fermenter bucket when I got one for 9 bucks with a much better valve.