Firstly, they are definitely not trusted. That's why they have negative trust on bitcointalk. They also accept money to list a coin on their site, which usually means that they don't care about the customers as much as getting people to list coins on their site. There has been a ton of people who has had their HitBTC accounts compromised even though there was sufficient security measures and it was unclear if it was a breach from the inside.

If you're talking about support being slow, HitBTC from what I gather definitely has some slow support responsiveness.

Do expect to wait up to a few weeks for your ticket just to be handled, and the answer always seem pretty automated. But their speed of deposits and withdrawals are probably around the same as other sites, although I definitely wouldn't use them if I were you.