by karlfast
The fifth and final ability is the least powerful when it comes to actions. However, it's a multiplicator for the victory points earned per city in a network. A completely unlocked multiplicator ability will give you five times as many victory points - nothing to sneeze at!
The people I play with view the network multiplier as so powerful that in most of my plays nobody will allow anybody to upgrade it beyond x2. It doesn't help with actions, as noted, but if the table doesn't keep it in check someone will run away with the game. The rule of thumb is that if you want the upgrade you should get it early because by mid-game it will be blocked and the cost of upgrading is too high -- so find another path to victory.
At the same time, while everyone wants to prevent someone from getting the multiplier, not everyone is willing to contribute a cube to blocking this route. So some players count on other players committing resources to this effort. Other players leech off their efforts. It's a small but interesting nuance in the game.
Hansa Teutonica is the game that tipped me from "these games are fun" and into buying lots of games, building a collection, talking about games on BGG, going to meetups, and turning this from a past-time into a hobby.