How Does the Nubia Z70U Compare to the Mix4? My Initial Impressions After Half a Day of Use

In one word, this upgrade doesn’t feel like much of a leap for me.
Firstly, the most obvious difference is the screen. Let’s not talk about appearance—between the 1080p and the 1.5K, they’re truly neck-and-neck. To my untrained eye, the only noticeable difference is that the MIX’s display looks sharper than the Z70u.

Otherwise, I think the displays are fine.
Secondly, weight. My MIX4 with a silicone case weighs in at 260g, while the Z70u with its included case is just slightly lighter at 258.9g. The difference here is negligible.
Thirdly, Nubia’s themes are embarrassingly scarce—it feels like the app names are practically bursting out of their icons (though later I discovered turning off third-party optimizations within the icons helped a bit).

Fourthly, as a former Nubia Z11 user for two years, I have to say the system feels significantly better now. Initially, I was worried about issues with push notifications for my frequently used apps. But after half a day of use, everything seems normal—even DingDing notifications work perfectly alongside WeChat.

Fifthly, I haven’t really tested the battery life yet; I’m still using the factory-installed charge. However, there’s something odd about the heating. After letting it sit in standby mode for half a day, I unlocked it around 9 AM, upgraded 11 apps from the app store, and sent some WeChat messages for about 10 minutes.

The phone got slightly warm. Huh? It shouldn’t be like that, right? In winter, after just 10 minutes of messaging and upgrading a few apps, it’s already warm? If it weren’t just a little warmer than body temperature, I’d swear I was holding my MIX4 again. Or maybe because I’ve been using the MIX4 for so long, I’ve lost my sense of what constitutes “normal” heat levels?

Sixthly, I don’t play many mobile games these days—I mostly stick to PC gaming if I’m playing dual-platform games. So, I downloaded “Challenger” and played a round. It felt faster to load compared to the MIX4, and the 60fps setting ran smoothly without lag during gameplay or settlement. The phone also generated less heat.

As for other aspects, I didn’t bother running precise data tests. For my personal usage needs, there’s really no discernible difference.
Seventhly, regarding the camera—I’m definitely an amateur—but from a general consumer perspective, the front-facing camera recognizes faces faster than the MIX4, the rear camera focuses quicker, and the final images come out clearer.

However, the Z70u defaults to a strange 1x 35mm mode when you open the camera app. The edges on either side appear distorted. Switching to 0.9x fixes the issue, but do I really need to manually adjust it every time I take a photo? (I took two screenshots comparing the MIX4—just look at the top and bottom frames to see the distortion in the 1x mode.

)
Eighthly, AI features are largely unnecessary for me aside from occasional translation tasks. Everything else is turned off.
Here’s my initial comparison with the MIX4:
Positive aspects:
1. The system feels more refined compared to the Z11 era—notifications and background management are much smoother.

2. The front-facing camera has a better hidden notch design than the MIX4.
3. The new processor performs well—the fluidity surpasses anything the MIX4 could offer.
Minimal improvements:
1. For non-heavy mobile gamers like me, the gaming experience is slightly better on the Z70u. Faster loading and settlements, but during gameplay itself, there’s not much difference between 50fps and 60fps.

2. The system has improved, but it still lags far behind competitors like Xiaomi’s Surge OS.
3. Weight difference of 1g is basically imperceptible.
4. Battery life and temperature performance remain unclear for now.
5. Camera-wise, I’m inexperienced, but having to manually adjust to 0.9x every time is inconvenient.

At this point, I’m already 60% inclined to return it. A $5000 upgrade that offers only these minor improvements isn’t worth it for me.
However, I’ll give it another couple of days to test the battery life. Last month, I spent 70 yuan on PDD to buy a replacement battery for my MIX4 and installed it myself.

From leaving home in the morning until returning at night, based on my usage habits, it still retains around 35% power. If the Z70u ends up offering similar battery life, then it’ll be a dealbreaker—I’ll have to return it.