Tried it. I created two notes, got their public addresses, and sent bitcoin back and fourth. The inconvenience I notice is that I must withdraw fixed amounts (e.g., 0.001, 0.005, 0.01 etc.). Fixed amounts isn't the problem per se. What might annoy someone is that you enforce an arbitrary fee rate (2500 sats per address). I don't get why you don't let the users choose themselves. At the moment, I have about 800,000 sats in notes, and I'll have to mix another 200,000, so I can merge them together into 0.01, to save 7500 sats in fees.
We could let users withdraw arbitrary amounts like before too after clicking a checkbox saying something along the lines of "I understand that if I withdraw an arbitrary amount my withdrawal could be deanonymized under certain conditions", but there are not many arguments in favor of it since the privacy levels increased by multiple folds with the introduction of fungible outputs, and if you are really that concerned about the 2500 sats fee you can just keep the balance on the Note until you reach a fixed amount that you can withdraw at once. Transfers between Notes are 100% free, not subject to any 2500 sats fee.
We can't let users choose the fees themselves because all transactions are sent from the same multi-sig so we can't really afford to have any of them stuck for a long time. Assuming the user chooses 0% donation if we pay more than 10 sats/vb for his individual withdraw then we're losing money. On the other hand in a month we lowered the fee 6x from 15000 sats to 2500 so this is already some good progress and cheaper than anything else, and depending on the profitability we'll eliminate this altogether.
You're also showing in the main page how many anonymity sets there are. Is it because it's trivial for an advisory to figure that out in the chain?
Our multi-sig is always visible at this address:
https://mempool.space/address/bc1qf8h5k6sash8007vpesymxkw2xsg5d0r3j4l5vmcrwpz2pqu66fjstzgd3rWe are showing the Anonymity set on the website too so users are aware of the exact level of anonymity they are getting when using Whirlwind and to make it easier for them to figure out when new deposits were made without having to check the chain themselves. Again this is public knowledge so there is no reason not to show it.