>>310820674
G2
+Better resolution, better lenses(?)
+Cheaper (unless you already have the base stations and controllers from a vive)
+probably more reliable

-worse tracking
-have to buy base stations and run a hybrid if you want full body
-worse controllers

Index
+Better refresh rate
+Better controllers (though they still aren't all that good)
+Better tracking 
+easier access to full body tracking
+Really good customer support

-Not very reliable, particularly in the controllers
-Expensive
-Kind of dated at this point (not very, but getting there)