Someone make a Shield vs Vita vs 3DS stat!

I think that hardware speaking you forgot the lack of buttons on the tablets, which make it unplayable and completely useless for any serious gaming.

Nintendo said the Wii U is has been making a profit since May of this year. Also let address one thing I find unfair about your comparison of these twp pieces of tech. They are both 299, however the Wii U isn't just a tablet controller its a game console which usually get at least one free game with. You're framing this discussion like the tablet is only 299 alone when isn't the case.

The Shield tablet is constrained by TDP requirements and lack of software. You can bet it's GPU won't get anywhere near 360 GFLOPs in a real world situation since it's widely known that these mobile hardware throttle clocks down quite agressively when being pushed, also, nVidia's specifications usually are made based on a perfect scenario, tablets don't have active cooling, so, yeah, performance is bound to be a lot lower. Also, being ran on Android, you can expect no game to take any advantage of the hardware, but it'll surely play existing games a lot better than other Android hardware out there, so at least you can have that if Android gaming is your thing.

I honestly think that this is the way Nintendo should go. Release a proper home console with a regular controller that, while not being as powerful as the PS5/X2, is closer to them than Wii and WiiU have been to its competitors. And then, make its handheld console more like WiiU's tablet controller with an 720p or even 1080p screen with the same architecture (but not specs) than the home console.

The catch? Well, there's 2:

1-With both devices using the same architecture and OS, all virtual console games and most eShop games will only need 1 version that can be played on both devices.

2-Use the handheld like Nvidias' Shield, so that the games of the home console can be streamed to the handheld and played with it while freeing the TV to other family members. So what WiiU wanted to do, but without the drawbacks that it has brought.

You can store WiiU games on any expandable memory you attach to it (the aforementioned methods I mentioned).

However, Nintendo doesn't recommend use of any form of flash memory because they have a limited number of rewrites possible before they start to break down, while HDDs are reuseable over and over and over basically until they wear out physically.

But which has better looking and better overall games?

Wii U, end of story.

And Yoshi's Wooly World.  Where else can you get a dinosaur made of yarn? 

At least the Wii-U CPU is far more powerful. ARM A15 is a ultra-low-voltage design with no real performance at all.

It's a good thing I buy consoles for their games, not hardware. The Wii U wins.