I got one installed yesterday
I also bought a few concrete foundation blocks to put under the barrels, they look better than the old block I had.
Here's a close-up of how they are hooked up. Each barrel has a 1/2" faucet so that it can be independently closed off and washed. The main faucet is 3/4".
There was a thunderstorm in the evening and this morning it looks like both barrels are 90% full