I've been trading on Poloniex for months and not had any issues. But with the substantial increase in users, Poloniex is unusably slow to make trades. Rates are changing multiple times every second and it takes over 10 seconds to place my buy/sell bid. In those few seconds, the price has already changed and it is impossible to make a bid.

I am looking for alternative exchanges which has had a good track record and works without these delays. Also, it should work on mobile. Any suggestions?