exchanges i think is better. they charge commission on winnings and they don't care whether you win or lose and it is less likely they will ban you, unless you are doing really provocative stuff there.
i agree not to take the road of multiple accounts. this things end up with tear in the eyes usually.
Try Orbit Exchange. It is backed by Betfair and it has very high liquidity. Never have i not matched by bets there.
I use crypto and i use the agent Betcoinbookies. 3% commission, no KYC, no deposit and withdrawal charges and fast payouts. So far no problem with them.