Here is a comparison between the two devices -Design and display
Physical dimensions of the Moto G 3rd Gen
are 142.1 x 72.4 x 11.6 mm, while the Lenovo Vibe S1 measures 143.3 x 70.8 x 7.8 mm. In the current scenario where one prefers thinner phones, the S1 makes an impact. The Moto G weighs a little heavier at 155 grams than the Lenovo counterpart at 132 grams. Both of them come with 5 inch IPS display. The resolution differs though. Moto G has a resolution of 720x1280 while the Lenovo Vibe S1 sports a full HD resolution. The pixel density on the Lenovo is beeter at 441 ppi compared to the 294ppi on Moto G.Hardware
Moto G is powered by the trusted Qualcomm Snapdragon 410 quadcore processor. The clock speed reads 1.4 GHz. Lenovo on the other hand is powered by MediaTek MT6752 Octacore processor running at 1.7 GHz. Though the configuration looks better on paper, Snapdragon appears more trustworthy than the MediaTek processor. The Lenovo Vibe has 3 GB onboard RAM in comparison to the 2 GB RAM on the Moto G. That makes it a robust multitasker. As for internal storage, the Lenovo Vibe S1 again takes the lead with 32 GB storage while the Moto G has only 16 GB. Even in the memory expansion option, you can expand the memory by another 128 GB in sharp contrast to just 32 GB on Moto G. Camera
On the imaging front, both of them equivalent with both featuring a 13 MP rear camera with autofocus. They do come with the regular set of modes and settings. Front camera however differs in resolution. Moto G has 5 MP front snapper while Lenovo comes with a 8 MP monster. Software
Here again it is tie between the devices. Both of them run on Android Lollipop. Moto G gives you a pure stock Android experience, while Lenovo has its own customisation. Battery
There is not much difference between the battery capacity between the two smartphones. Lenovo Vibe S1 has a 2500 mAh Li-Po battery, while the Moto G has a 2470 mAh Li-ion battery. Lenovo has stated that the Vibe S1 has a backup of 11 days in terms of standby. Motorola on its can have a backup of around 12 to 13 hours of regular usage, while Lenovo has not come up with details on it. Price and availability
Lenovo Vibe S1 is priced at Rs. 15999 and is availble for purchase on Amazon India. The Moto G on the other hand is slightly cheaper at Rs. 12999 on Flipkart.
It is advisable to go for Lenovo Vibe S1 because of a few advancement that it promises to offer. Both the phones coming from the same manufacturer ( yes, for the information of those who are not aware- Motorola is now owned by Lenovo), there should not be any concerns as far as after sales service is concerned.