When you say cash out you mean move to fiat or instantly move it to your fiat bank? I'm having problems with the 3 to 5 day lag on the move from USD Coinbase to USD Bank of American for example.
Hmm - I guess that must be something specific to your country (US)? I am in the UK here. My process is as follows:
1. Send BTC from my wallet to my Coinbase account
2. Set a market order to sell BTC for GBP instantly at market value (my local currency)
3. Withdraw GBP from Coinbase to my UK bank account
The above processes are all instant, even the withdrawal of cash from coinbase to my bank account. Literally, as you press 'OK' to confirm withdrawal, at the same time I get the notification popup of deposit to my account.