I will do my best to keep this relatively concise.

In a nut shell, you set up a channel with another node via on-chain transaction. So if you contact a partner and send 1M sats via on-chain, you have OUTBOUND liquidity. This means you can SEND up to 1M sats, but can't receive anything.

Alby hub let's you pay a lightning service provider so that they'll lock Bitcoin up. So an LSP will create the 1M sats on-chain transaction which gives you INBOUND liquidity. Meaning you can RECEIVE up to 1M sats but can't send anything.

So you're trying to balance inbound vs outbound. I need to be able to receive as well as send. It becomes a bit of a juggle at times. Nothing super crazy but it takes deliberate action and planning.

And because it's lightning, the LSP can unilaterally close your channel at anytime. So it may happen at a bad time when you were expecting to need liquidity.

On that same note though... You can use lightning in a way that mitigates the need to pay a LSP. So, you can open a big channel say, 3-10M sats, using your own Bitcoin. Then once the channel is open send half of it to another wallet like aqua or strike or Phoenix. Then you'll have a channel with half inbound and half outbound liquidity. But that depends on your comfort level.

I try to keep around 1M sats ready to send at any given time. That way it's not super terrible if it's lost. Gotta think about this as cash in your wallet. How much are you comfortable keeping on you?

The other downside with running alby, your node needs to be online at all times. If it doesn't have access to internet, you can't reach your funds until you turn it back on. Even Zeus is really only connected while you have the app open. That's why it has to sync every time you open it.

Tradeoffs.