So all other stuff aside, I've been thinking about the cost/reward of GE5.
I don't know much about the encounter rewards other than what I've read here...which hasn't impressed me.
In looking at the new buildings from level 5, I don't see how they're better than ones you can get elsewhere with much less effort. For one thing, the main building, which is admittedly nice while it lasts, has to be demolished and rebuilt every 4 weeks and that can only be accomplished if you complete GE5 all 4 of those weeks. And while the boosts it provides are nice for other areas of the game, they are woefully inadequate for making much of a difference on level 5. Unless, of course, you remake your city to drastically increase your defense army stats.
The secondary chain building would be mildly attractive if you could get it another way, but not at the cost of having to complete GE5 multiple times. Again, the boosts won't help much, if at all, with level 5.
It might be a little different if the level 5 buildings made it significantly easier to complete level 5 in the future, but they just won't. And what sense does it make to remake your city for buildings and a feature that won't make your city any better than other similar event/special buildings?
When you top all that off with the fact that all that defense you have to add have virtually no other use in the game, it really calls into question the wisdom of bothering with GE5.
Sadly, just adding a level that isn't worth the effort wasn't the extent of this change. They also significantly nerfed rewards on the existing 4 levels of GE.
My takeaway from this change is that not only do I see no reason to bother with GE level 5, I also see less incentive to expend much energy on the first 4 levels.