Not gonna mention any names but... saying "THIS EXPANSION WILL LITERALLY BREAK YOUR GAME" is a really dramatic over exaggeration lol. I have a pretty low end computer by any standards and it handles seasons fine. There aren't many bugs that I've experienced, but the ones that are there are pretty minor and fixable, such as stinky leaf piles staying around for months and sims getting stuck under staircases.
I think seasons is one of the best EPs for ts4 yet, and it made the game so much more immersive and fun. I think you should definitely get it if it's within your budget!