Tenga has been my go-to for years now so I was excited to try this out and honestly wasn't disappointed. It's definitely not perfect, as I'll get into, but it's definitely one of the best I've tried.
Since I like to end on a positive note; I'll start with the negative:
As others have said, there's some leakage during use. I haven't tried it with other lubricants, but Tenga's brand does leak out making cleanup more difficult. On the topic of cleanup, it's kind of a pain since it requires a more time intensive process due to the more complex mold. After cleanup, trying to dry it is difficult due to the notches on the side that are supposed to hold it being extremely small and easy to have it pop out of, which can lead to some trouble with getting it in the drying position.
All that said though, the actual experience of it in use is wonderful. The ability to make it air tight combined with the vibrations leads to a unique experience that makes orgasm a dream. On top of that the multiple settings help prevent getting bored if you masturbate often. Applying lube is also much nicer and lets you distribute it more evenly that most other onaholes. The main body of it is also much softer than most onaholes I've tried, allowing the vibration to massage in a more comfortable manner than I imagine typical material would.
Plus afterwards you feel like you fucked a robot which really just sells itself