As someone who's had one too many Stanley tumbler spills in my work bag, I was eager to test this silicone accessory set. After a month of daily use, here's the real tea.

The Good: The straw covers are absolute game-changers - they create a perfect seal that survived being tossed around in my backpack. No more mysterious wet spots! The square stoppers also performed well during my commute, keeping my 40oz Stanley leak-free even when it tipped over in my car cup holder.

The Not-So-Good: That darn round stopper! Like many reviewers mentioned, mine constantly falls off into my drink. It's become a weird hydration game - how many times will I fish it out today? The set could really benefit from clearer instructions too; it took me three tries to figure out the proper straw cover alignment.

Real-World Testing: I subjected these to every scenario - gym bags, road trips, even an unfortunate drop down a flight of stairs (RIP my phone). While not 100% spill-proof (don't turn it upside down!), they reduced leaks by about 90% compared to using the tumbler bare.

Final Verdict: Worth it for the straw covers alone if you're tired of cleaning up spills. Just be prepared to play hide-and-seek with that round stopper. 7/10 - fixes Stanley's biggest flaw but has room for improvement.