Yes, I just used it 2 days ago to be exact. You have to create an account first before you can exchange your coins. Actually its my first time to used them and I've been reading a lot of reviews and its seem they got a good rating as compare to Shapeshit, I mean Shapeshift which the fee's are ridiculous high. I exchanged my Ethereum to Bitcoin. I was nervous at first but then I go and went with the transaction. Of course I double checked everything before sending it out. I did it when I was about to sleep, so I don't know how long the transaction takes place, although my Ethereum transaction (with 50 GWEI) was immediately, I was worried about the conversion and the deposit on my account. But Lo and Behold, when I wake up changelly confirmed that my transaction is done and when I opened my wallet its already there.
. So I can vouch that they are legit.
Edit: My transaction is .5 Ethereum
only.
I have made a lot of exchanges with different coins on changelly before and i never got any issues with them, the only problem there is that they charge unexxpected fee to process exchange through their platform, however i would still say changelly is more cheaper than regular wallet like coinbase, btc.com but as your topic is to know trusted exchange service, i think we have guarantee for our coins safety when it comes to a huge amount, whether it is shapeshift, or changelly, you should exchange in splits, not to send whole amount in single transaction if funds are huge
Shapeshift charges more If I'm not mistaken.