I owned both and a few other (magnavor, algae free, mag float extra large). They all good for cleaning your glass, but IMO no mag cleaner can take care of the stubborn coralline algae.
Manual scrapper is the only tool that works for me.
The only way the mag cleaner might be usefully is that you clean your glass DAILY!
Oh! forget the Tunze magnet care. it's awkward and small handle that give you finger cramp after using it.