It really depends what the end goal is.
Would I suggest them for optimal airflow? No, for <$10 a piece they're hardly going to be the best engineered item in the world.
Would I suggest using them for the "perfect" RGB look? Probably not..... I highly double they'll look as "good" (subjective) as they do in their pics
Would I suggest using them for what they are, cheap fans with RGB? I don't see why not.
They don't appeal to me... I wouldn't bank on them lasting a long time... and they'll require use of the remote (they're not going to integrate into any software etc)...... but I don't necessarily see any harm in them.