Sorry, incredibly wrong specs and there won't be a handheld version of anything. There will be a handheld and a home console.
First of all: I expect there to be a home console and a handheld that share the same architecture and operating system. So we are probbaly talking about the same thing, just using different words.
Second: If you have insight into these kinds of things, I'd be glad to learn more! Here's what I did: I looked at Nintendo's past consoles and handhelds and it turned out that aside from the Wii each console / handheld from the GC / GBA generation onward followed Moore's Law. The Wii was the exception to the rule, because Nintendo designed it to be a disruptive product. GBA to DS, DS to 3DS, N64 to Gamecube and Wii to Wii U all followed the same trajectory. So I concluded this would apply to NX as well. When I did the (very basic, uneducated) math for RAM, CPU and TFLOPS, NX home console sat exactly between PS4 and Xbone in power (if released in late 2016). The next handheld was more powerful than a PS Vita but not by leaps and bounds. Again, just doing some basic maths. I'm not claiming to be an expert.
I also looked at the rumors circulating around the internet. We have Square Enix who almost-confirmed Dragon Quest XI for NX and rumors pointed to NX being roughly as powerful as PS4 and Xbox One. And to me that makes sense. Nintendo wants third parties to be on board and having a console similar in power and architecture to PS4 and Xbox One would make it easier for third parties to develop games for Nintendo's console. At the same time the console wouldn't be more expensive: Nintendo never made a console or handheld more expensive (or powerful) than it had to be. Coincidentally, this power range is exactly what the power trajectory of Nintendo's past consoles would suggest as well. It just all falls together pretty nicely.
So, that's the logic behind my claim. But I'm no expert, so if you have inside information I'm happy to learn more! Especially why these specs are "incredibly" wrong (why not just a bit?).