The best sites for me are:
Poloniex - They are one of the best trading site and they are doing their best to maintain their reputation and they always maintaining good amount of coins and only limited based on their activeness.
Bittrex - Most of the new legit coins are getting here which give you advantage to buy it on an early age.
Yobit - A lot of coins to choose from, if you know how the whales move then you are going to make a lot of profit.
I agree with your list and description. So far,Poloniex is good and neat to trade. Very many traders and transaction are fast,just be very careful and vigilant because you may lost very fast too. Bittrex, I like it because many big traders also, and the the one that I like is that it has no trollbox, whales and speculators cannot dictate nor induced FUD.
Yes to those site; bittrex and poloniex have a lot of whales on their site and that is why it is good to trade on them because you can ride the waves of the whales in every coin and if you jump to the right time then you will earn profit because this past few weeks the price of the altcoins goes up pretty high and now they are dumping and that is a good buying opportunity because after the price of bitcoin goes down, the whales will start to play again.