The good exchange I think is very simple..
- responsive customer service
- cheap fee (maker, taker & withdraw)
- high level of security
- have a lot of pairs (BTC/ETH, ETH/LTC or others)
- have very few complaints (minimum 0.3% of total users)
I don't like the KYC verification and I will never send my personal data online except for local KYC and that is why I used bitcoin is that you don't need to exchange your BTC to local fiat without verification. However, the problem these days almost all exchanges are now asking for KYC even claiming ICO requires KYC which is not fair.
I don't like KYC on the gambling platform but for exchange I think it's very important.. an exchange which enforces KYC, of course, monitors the movements of its members and it will reduce money laundering, we cannot deny that corruptors, weapons dealers and drug traffickers use cryptocurrencies for their transactions. so my conclusion, KYC is very important in exchange.