Fazit at first -I like it :-).
Lets start with the cons.

Cons:
There are several shortcomings for my use case, such as the inability to add tags for categorization or selecting multiple items for tasks like deleting 20 items at once, which must be done one by one. Sometimes, the displayed items and icons are difficult to differentiate, especially on a 5K monitor. It would be beneficial to customize the interface in more detail. Lastly, I miss a filter for already invoiced and paid items, as it’s crucial for me to see which tasks have been invoiced and which are still open, as well as which ones have been paid. As well i would like to see on my timesheet if a item is already on an timereport that was generated or shared with a client. At the moment you have to remember it or fiddle aaround to check on that.

Pro:
It has a ton of configuration options and is very adaptable to different use cases. You can add items that may be needed in certain situations right where you are. For example, if you need a new category or task while tracking time, simply click the plus icon next to the dropdown items and add what is needed. This way, there’s no need to search around or navigate away from your main task, which is crucial for efficiency. You can stay focused. You can also define custom fields to meet your needs for gathering the right information for your poject needs. I love that there is an app for my smartphone and for the mac that is neat and provides everything I need to start and stop a timer and select where the time should be booked. Yes, it has many other options, but that’s what I primarily use it for. No need to work always in the web interface.

There is a bit of a learning curve, but if you're not new to time-tracking apps, you'll become familiar with it in a short amount of time. Hopefully, development will continue fast, and we will soon be able to select multiple timeitems for editing (deleting, moving, etc. :-)other categories or clients). I'm happy that i tried it and will stay with it.