This wad ignores much of what the SRB2 community at large considers "good", but ultimately proves that you don't have to be conventional to make a good levelpack. It uses its linear level design, forced character switching, and occasional time limits to provide highly focused challenges that force the player to adjust their approach. Despite how tight and deliberate this wad is, it never oversteps into kaizo territory; if you've mastered the vanilla campaign and are good enough with the 3 base characters, you can probably handle ASfAEe.
That said, not all levels here are winners; there's multiple of these weird open intermission levels that have a bunch of irrelevant stuff littered around a pathetically easy path to the goal. I'd think these are here for hidden emblems, but there are no collectible emblems in this wad (despite multiple intangible ones being scattered throughout the stages for whatever reason). Beyond those, there's multiple levels that feel too easy or too hard for their point in the game, or are just plain baffling (was Rerun Site really necessary?), and even levels I consider good suffer from oddities like arbitrarily excessive amount of rings and monitors. Specifically regarding Final Judgement, golden monitors exist for a reason. If you want to make sure the player has access to a specific power-up, put down one of them in a golden monitor, not 20 or so in regular monitors.
ASfAEe didn't blow me away, but it gave me a fair and unique challenge and made me consider if this community really has level design down to a science, or if it's just found its comfort zone.