Katakuri is a top 5 OP character for me, but the reality of his Mochi fruit is that it is pretty much an upper Mid-Tier Devil Fruit at the maximum.
Assuming for a minute that eating Katakuri’s DF instantly grants you intangibility/shapeshifting and that this isn’t a product of Kuri’s own fruit mastery/awakening, this is pretty much the only aspect of his fruit that makes it unique and/or powerful. Mochi as a summonable substance is a pretty weak element to have control over, as its stickiness is not enough to consistently restrain people.
Being able to shapeshift around Haki attacks is great, but this is something mainly attributable to Kuri’s CoO and not his DF itself. Furthermore, shapeshifting around Haki attacks isn’t even unique to kuri, as any competent logia/“special” Paramecia can also seemingly accomplish this.
Really there is absolutely nothing overpowered about Kuri’s DF, the real thing that makes Kuri dangerous is his observation Haki as Luffy pointed out, and his Mochi DF in and of itself is no better than Monet’s or Smoker’s fruits.
Would I eat Kuri’s DF? Sure. There aren’t very many fruits in the series that I would outright not want to eat, and Kuri has already shown that he can make even a fruit that is theoretically Mister 3 Tier into a true YC1 caliber ability, but there are other fruits I would definitely prefer.