Smartwatches are not necessary but only luxury, samsung gear s2 is no exception. My elder brother bought this smartwatch a month ago for 23, 000 and I also tested it for a long time, here is my review: -
Powered by exynos processor, Smartwatch is flawless.
Display is crisp and good.
Internal memory is 4gb with 512 mb of ram, enough for all smartwatch apps.
However smartwatch apps are still in low number therefore you may need to consider whether you truly want to buy it or not.
Only con is its very very expensive, even smartphones are cheaper.