Traditional is used in RoC (Taiwan), Hong Kong, Macau.
Simplified is used in PRC (China), and the Chinese communities in Singapore and Malaysia.
Usually someone who is familiar with traditional can read texts in simplified and vice versa. That's because of context (and oftentimes the general "shape" is still there). Many, if not most characters are identical in both the simplified and traditional forms.
Some of the simplified strokes like the 讠radical are based on cursive Chinese
On printed text and computers, the difference is quite apparent, but with handwriting nobody writes each stroke individually like that of typefaces, it's like expecting people to write English in helvetica or times new roman.
I think for handwriting / cursive, simplified looks better because it mimics Chinese calligraphy, but for printed typefaces, traditional (usually) looks better.
That said, it's a bit of an eyesore when you get characters with like 20 strokes and it usually ends up looking like a block of scratched ink, especially if the font is like < 9 pt, you can barely read it and it looks cluttery. There's less occurrence of that with simplified.