I fall into the “I got it for free, since my fac mates bought the offers” category and got all tickets from the milestones, so can’t comment from a pure F2P faction’s viewpoint, but for my category, the rewards were really nice. Will get me that Laopo I always wanted (for some defensive tinkering), but never selected in the choiceboxes as a more atk benefitting toon was available… Also, got plenty of trainers and also earned quite some toon XP, since I ran the maps with Pam lead… Player XP could also be earned in quite a high amount (like 1-2 player levels, depending on territory boosts).
Brings me to the difficulty - understand that people could have struggled, especially on the final stages of each act, but for me, Pam lead (i.e. no real fight boost except her 15/35) was viable thanks to a T4L120 Frost and a T1 Kenny who ensured survivability of the team, even against the hard lineups. Challenging, but beatable and yet - as @Moog piinted out, way too grindy.
Even with full 7 days, completing the maps took a lot of effort, especially if you couldn’t run auto (I myself could, except the finals to avoid rushes/actives against walkers that could lead to your team dying). I completed the harder maps, but timed out on the easy at 8-6, so didn’t get the 6* box (no biggie, have all toons, some in dupes).
If your faction got all pages, you had enough tickets to fail multiple times and still complete everything - sufficient to learn which stages you can breeze through despite high rating and which you had to really focus on with a balanced crit team capable of bringing down an S-class team (controlling actives not wasted in the first 4 walker stages was the key). All you needed was generous sponsors, or a little spending, but what you needed most was too much time on your hands…
An event should be a bit more than just some offers and roadmaps (looong, tedious ones). Especially if the roadmaps lacked any coherence, or semblance of a story. And with the blog blunder (initially suggesting the first milestone should have been 1 page, later updated to 5, besides posting to watch out for free ticket offers that never appeared), I can’t rate it better than 6. Can fully understand if lower level players or pure F2P (or smaller) factions would rate it much lower.