Among the shortcomings, I would probably note the small number of supported networks. It would not be superfluous to have TRC20, it seems to me that USDT TRC20 is used by a much larger number of users than ERC20, for those who make frequent exchanges will pay attention to fees.
I paid more attention to privacy than calculate the fee, because eXch already has low fee currencies such as monero and litecoin.
Like Monero, So far the fees offered between 0.1 - 0.05 USD. if it's that amount is quite expensive for your, there is Litecoin which might be set below than Monero.
About Affiliate program, how to divide it?. because when registering the exchange didn't ask bitcoin address to receive preofit.