I also have bought WagonR JDM and i am loving it , i sold my cultus 2015 and bought it . The specs as mentioned by hamza are best available . and i am loving the upgrade.
The pros i like :
acceleration, space, comfort , mileage
anything just go for JDM. Mira on the other hand has poor ground clearance. so in my opinion go for JDM WagonR/ Stingray. ( parts are easily available)
WagonR vxl ( PKR ) is not well equipped and also its shape is also rather pathetic, since its PK the built quality is also poor.
The price difference is not that much as compared to both the WagonR's
Rest is your own judgment .