They have not been implemented at DLR yet, and no start date has been announced.
Having used MagicBands at WDW, I do find it easier - especially park entry. It takes a lot less time to scan a band than for people to pull out their phones, open the app, and have them scanned.
I'm not a fan of using a phone the way that DLR expects people to - I actually printed my Magic Key code onto a card so that I could use that instead, and it's so much faster than dealing with a phone.