Motorola Moto Z2 Play is costlier than Motorola Moto G5s Plus making a price difference of around 10k but There is not much difference in features they provide. Lets compare them in detail to decide to best one for you.
Slimmer: Motorola Moto Z2 Play has a thickness of 6mm which is 25% than 8mm thickness of Motorola Moto G5s Plus. Slimmer devices are easy to carry and look more fashionable.
Light Weight: Motorola Moto Z2 Play is 13% lighter than Motorola Moto G5s Plus. Light devices are easier to hold without tiring your arms.
Dual Camera: This is where Motorola Moto G5s Plus overtakes Motorola Moto Z2 Play. Motorola Moto G5s Plus has a dual camera which is useful in enhancing certain effects like blur, zoom and wide-angle photos.
Verdict: I recommend you to go for Motorola Moto G5s Plus because it is cheaper and also have a dual camera which is more useful feature.