CoinJoin main advantage is that it allows you to mix your coins in a decentralized way. You don't have to trust any third party.
When using a regular mixer, you have no guarantees that they don't keep logs of your activity/personal information.
I like this solution of decentralized way to mix the coins. However having only 0.1xxx coins for each time you queue is a bit long process and also it's petty that one can not mix anything below 0.1xxx
They can have some more target categories like 0.001xx, 0.005xxx, 0.01xxm 0.05xxx, 0.2xxx, 0.5xxx and even more instead of only 0.1xxx