While at first they may look similar, there are lots of differences that make Premium Topos far superior to free ones. Let's have a look at both.
Free topos:
Can be made by anyone
Are not quality controlled and usually incomplete
Can only have a maximum of 20 routes and 7 topo images (old free topos might have more information than this)
Don't have descriptions, route properties or sector details
Are free to use and authors don't get paid when climbers use the topos
Can't receive suggestions from other climbers
Can't have permanent maintainership by a team
Premium topos:
Are always maintained by a "team" in 27 Crags
Have as complete information as possible and there's no limits in the amount of content per crag.
Are quality controlled and evaluated before publishing
Only users with a Premium subscription can see the images of Premium topos
Premium authors get paid when the topo is used
People outside the team can make suggestions to Premium topos
Team members can use their topos without having a Premium subscription