The Lenovo Z5 is unlikely to show any lag with the new Snapdragon 636 chipset that is powered on a 6GB RAM. The phone with its big screen is good for gaming and can run heavy apps as well.
It will be running on Android 8.0 and ZUI 4.0.
Lenovo Z5 Processor
|Chipset||Qualcomm SDM636 Snapdragon 636|
|Processor||Octa-core 1.8 GHz Kryo 260|