As far as I use HitBTC, I don't have any complaints other than the fee that is big enough for now. Well, I hope HitBTC can be like it used to be 
Well, I was dealing with them in a cooperative way (business) and was quite amazed how much BTC they ask for simple technical tasks, even with that huge amount of competition in the field, where each and every single exchange should make the utmost and cooperate in best manner with the projects that are listed and/or offer to pay for a listing.
From a private stance I will anyway avoid using them for the ridiculous high fees.
Next please...
Right now, I am one of many people frowning upon the terribly high fees of HitBTC. It so happened that there were specific altcoins in the past which were listed on HitBTC with a not-so-bad volume which were not admitted on other good exchanges. During those days, it was already a huge achievement when a coin is listed on Bittrex and Poloniex. And we all know that getting admitted on those exchanges is as hard as getting admitted to Binance today. That's how I got into HitBTC, and in cryptopia, among others. Until now, I am still doing some small trades in HitBTC and for a few years already I've no serious complaint against them.
But, just the same, I am fully aware of complaints after complaints raised against the exchange. They need to resolve them as soon as possible or else, just like Yobit, their brand is going to be equated with scam/shady.