Helps users a lot with typing speed and even memorize where the keys are on the keyboard I went from 25 WPM to 110 WPM in a few months. Personally I love the site. The only thing I don't like is the gold memberships because for people who can't afford it don't get to enjoy it as much as the other users. It is also very expensive for some.
But overall personally in my experience I find Nitro Type to be a very well built and helpful site.