Honestly... none. I don't see these tokens getting up in value at the moment. TPU is having some delegation bonuses as far as I know, but I don't believe investing (in the real sense of the word) in STEEM eng. tokens will bring anything good. And I'm sorry to say, but the Steem engine platform is let's not say miserable, but hard to use and lacking data. Esp. for those who want to trade. So IMO Steem might be your best choice at the end of the day.