M2, even if it require more powerfull server side resources, generally works more straight and quicker, especially all related to cart/checkout process, so from this point it will be more effective on sales then M 1.x version (checkout process speed frustrated a lot in M1, keeping thoughts about customers which simply abandoned their orders due to that).
Varien Dev works great, so removed many bugs and improved and again improved with each version update.
We already have 2.2.2 version, so tens version releases were produced in past 2 years. for me M2 currently rock and solid