Better in what way? These decisions come down to personal preference because pretty much every bike within the same price range is going to offer a similar level of quality/performance. The question is, what do you value?
I tend to be pretty practical, so if I were deciding between the two, I would go with the Stumpy mainly because it’s a 29er. No, I don’t think there’s a big performance difference between the wheel sizes, but all my bikes are 29ers so that just makes it easier to swap tires, wheels, etc. I also like to geek out on tech, and the Stumpy has a lot of new/interesting features like the chainstay protector, SWAT, etc.
What I like about both bikes is that they come with 2.6 tires and they have clearance for 2.8 tires. 27 is lighter and more playful. 29 has better rollover and is more capable when the going gets rough. Myself, I like 29×2.8 tires on i30-35mm rims which provide amazing rollover, traction, flotation, and cushion. So, I would go for the Stumpy. Whichever bike you pick, you can’t go wrong as both are great bikes.