I was the same way at first! My wife, her sister, my sister, all loved theirs...I was initially a skeptic of Yeti mugs and didn't understand why everyone and their mothers had one. Now I have two.
These things are truly like a thermos (without fumbling around with the lid) and keep liquids hot or cold all day long. Now I'm a believer and enjoy the large 30oz travel mug daily.
Washing the caps on regular travel mugs was always such a pain, so that magnetic sliding cap... *chef's kiss*