Dash and Monero are at comparable volumes right now, I question which one will certainly win, from the head to head battle. best to become diversified though
Two totally different projects nowadays. Monero is still focused on fixing their privacy issues whereas Dash is focused on mass adoption scaling and being easy to use digital cash.
Monero has not had the best of luck in the privacy department latley....
A well-respected cryptographer earlier this year released a tool called http://www.monerolink.com, where you can link all transactions from 2014-2016 with 100% (due to blockchain timing analysis apparently), and all transactions from 2016-2017 are linkable with a probabilistic distribution dependent on mixin size. So they have a table on the site, 1 mixin transactions are linkable 86% of the time, 10+ mixin transactions are linkable 22% of the time. Monero has fixed this bug since January of this year, but if you used monero on a DNM between 2014 - Jan 2017, BEWARE!