I don’t like how verbose Pascal-like languages are. I don’t want to have to type tons of keywords to get anything done. Curly brackets are a big improvement over pairs of “begin” and “end” all over. Makes it hard to see the forest for the trees when skimming some code to figure out what it does. That on its own makes something like this a complete nonstarter for me, leaving aside issues like support, quality of imple…
(Granted I am touch typing and also using Colemak layout, so rarely ever move my hands. For people that hunt and pek, I believe curly braces are easier to type.)
I don't think there is much practical difference between curly-braced vs keyboard based syntax. Both are similarly easy to read, especially with syntax highlighting. After a while, your brain will automatically parse "begin" and "end" as a symbol, same as curly braces, so you won't notice the "noise".
As for the pros and cons:
Pascal style syntax is slightly better for new people learning to program. Learning how to even type those weird curly braces and understanding the difference between all the styles of braces just takes focus away from actually learning how to program.
Curly braced C-style syntax is better for people that already know how to program because everyone is already familiar with at least one curly braced language.