Polo is good! I literally have never opened a support ticket there and I use them a lot, for many years, with a small exception the period when the platform had been acquired from Goldman Sacks!
Their interface is quite easy to understand and almost everything runs smoothly. Of course there are some incidents that are not positive at all, such as downtime trading periods during some volume picks. But again which exchange doesnt have them? Such incidents were more frequent before, now are rare. I personally have not experienced one for a long time now.
Also the withdrawal fees are quite reasonable. For example and for the time speaking, it is 0.001ltc, 0.0005btc, 0.05xrp, 0.01trx. The least reasonable fee is for withdrawing doge which is 20 of them.
Lastly, KYC is not mandatory. Someone can open an account at their platform only with an email. Of course there are some limitations at such accounts, such as margin and futures trading and withdrawing ammounts, but nothing that an average user cannot accept and handle.