The specs on the Internet are not quite right.
I don't know if there are more than one version of ZTE Blade A520, but my ZTE Blade A520 actually have 8GB of onboard storage, 1GB of RAM, 8MP & 2MP rear and front cameras respectively. It does show Android 7.0 but a few features such as split screen functionality and Google Assistant are absent. Performance is good given its price point. Its UI is MiFavor UI 4.2, just typical iOS-like UI and hardly customizable. The speakers are quite loud but they are back-firing causing it to be easily blocked. The display is 720p and I think mine is typical IPS LCD, so no need to explain on that. The cameras are what people can expect from a 50$-100$ smartphone. This phone does not handle games well, even basic low graphics games. I've noticed lag in every third party apps especially games. The battery life of this phone is not good. I have to charge it at least two times a day and because it doesn't support fast charging, it takes more than two hours to reach 100\%. Overall, there's nothing much to expect from this phone. If you ever get one, don't regret it. It's not the worst phone.