Hi…In my opinion they are all inferior Chinese models and at that price all your doing feeding the Chinese companies behind them. Aoyue is emerging as popular but keep in mind a few years ago all these brands were obscure and now people are importing them and they are doubling the cost to the consumer.
When I purchased my Yihua 936 stations from Hobby King they came to about £6 each now they are about £12. I also kept an eye out and picked up the Yihua 858D hot air station for about £22.