Title: Great until it needs cleaning
Review: Like most reviews here, I loved the tumbler and it worked very well. Coffee stayed warm for hours. I tried my best to clean the lid and kept it okay but after six months I stopped using this because of gunky build-up that was impossible to remove. I was eventually resorting to using small brushes and toothpicks to try and scrape it away but it was too inaccessible. DIshwashing didn't work nor did soaking. Eventually a moldy odor started to form and that's when I decided to throw it out.
Is this product review negative?