I just made my second exchange with Changelly yesterday. I was expecting it to be really slow, like last time, and it was... It took 9 hours from start to finish. However I was expecting that and I got a good exchange rate getting XRP for BCH.
I will continue using this service for holding the exchanged crypto, even though I'll be expecting it to take several hours to to make the exchange.
That said, I wouldn't recommend it for day trading or anything of the like.
CryptoSplasher