Pro Fast, easy to use interface
On desktop, tasks are assigned to a single line. To see the full description, you can hover over that task. Editing can be done by double clicking, and re-ordering the events are as easy as dragging them around.
It also supports markdown - a common web formatting tool that allows italics by putting single asterisk (*) around words or phrases, and bold can be done by using two (**) before and after the phrase you want to be bold. It can also handle links by putting the text you want visible in square brackets, and the link in round brackets so this: [Slant Homepage](https://www.slant.co] would look like this: Slant Homepage
Pro Very focused, allowing it to be the best at one thing
Instead of trying to be a both a calendar and to-do app, it focuses much more on the to-do aspect. There is a calendar view, however your tasks aren't organized by time - just by order. You can reorder the day's events, and if you don't get them done they will automatically roll over into the next day, so you can be sure that you aren't ever missing anything.
Con Subscription based will cost money each month
Instead of a single time purchase, Teuxdeux costs $3 each month, or $24 for a full year. There is a free 30 day trial, so at least you can try before put any money forwards, but a one time fee - even if it's $10 - is cheaper in the long run than a few dollars each month.