Right now there are four variants of the Hybrid Maruti Suzuki S-cross. They are:
1. Smart Hybrid Sigma (Rs. 8,80,689)
2. Smart Hybrid Delta (Rs. 9,92,689)
3. Smart Hybrid Zeta (Rs. 10,43,689)
4. Smart Hybrid Alpha (Rs. 11,43,689)
As you can see, Alpha is the most expensive one and there is an increase by 1 lac for each higher version.
According to me, the "bests" would be the Alpha as well as Zeta variants. Both of them are almost similar. Zeta is the top variant whereas, S-cross Alpha is richer in terms of features.
Maruti Suzuki has this range of vehicles which are called Smart Hybrid Vehicles by Suzuki (SHVS). These are hybrid systems that combine both a petrol/diesel engine with electric power. This system helps to make the car more affordable by increasing fuel efficiency and the overall performance of the car. It also reduces carbon emissions as compared to other cars and is better for the environment.
Earlier Maruti Suzuki S-cross was available with a 1.6-liter diesel motor but that has now been replaced with a DDis 200 Smart Hybrid Diesel Engine (1.3 liters) and is paired with an integrated starter generator. The fuel efficiency gets improved because of the additional power and also improves acceleration and overall performance.
Now, to answer your second question, there are a lot of additional features in Alpha when compared with Zeta even though the specifications are the same. A few of the additional features that I know of are: