Invasion was fun at the beginning but now it feels like a chore (i sometimes skip).
At first Mods were a small improvement (not really necessary) but after two increases of the values they are a must have. They will be even more important with the upcoming upgrades.
Instead of one (optional mod) we need now 4 of these must haves. Thats a total of 60 for your best heroes. Nobody knows if there won´t be more slots for mods in the future.
You get one free and one for cheap (per week). The other two are outrageous expensive.
So you need 30 weeks if you spend little money down to 15 weeks if you spend 80 Dollar a week just for the mods.
The consequence of this will be an ongoing stream of people quitting the game when they realise that the game is from now on all about Mods and Invasion.
For now i will keep playing and see what happens during the next weeks but i will not spend any more money.