I've been a bit torn over this one. But it's still very early and I should probably just hold on and see how it goes. For me, with the whole spoiler process they do, very few sets (if any) look amazing right out of the gate, but as more information comes in, stuff that looked underwhelming at first starts to make sense. That being said, I'm pretty hesitant on this one. Moreso than normal. They haven't been doing this new set schedule for very long and this set itself is only just starting to be spoiled, but already I think that I'm seeing a pattern. Pull out the stops for the Fall large set and give people what they want, use the Winter small set to complement that, then in the Spring come out with a more experimental and less refined block. While this would allow for variety, it would eventually cause problems. Hopefully I'm wrong and extrapolating way too much based on SoI Block. Time will tell.
That "punch card" looks atrocious (and isn't a punch card, so them calling it one is kinda embarrassing).
Not seeing any appeal to brick counters, Embalm, or Exert so far. Brick counters just look like a flavor-driven repainting of ground they've already covered, and seems like the exact wrong approach to flavor, but I'll wait to rant about until after making sure there isn't some really cool bottom-up thing going on that I'm somehow missing. Embalm looks like a hackneyed attempt to recreate the success of some of their more outlandish design successes. Exert could turn out to be cool, but I'm suspecting they'll try it out for this one set, decide they've explored the design space on it and that they'll maybe bring it back some day but probably not, and then it will become part of the pile of complexity creep in the general gameplay of Magic. Another one I could rant about later. No, actually, let's do it now...
So WotC have been clear that one of the problems they recognize in the game is complexity creep, that as more and more concepts are introduced in the game, the more overwhelming it is for newer players who aren't used to all of the details. In particular, they got worried about this with Time Spiral Block (the best block), as it had lot of mechanics. But since then, they've gone on to make lots of keywords, and they've gotten into a model where they need to meet a quota of new keywords for new sets. When sets are new, they release materials explaining the new mechanics, they include little reminders in things like booster pack inserts and those books that come in fat packs bundles. Players get familiar with the keywords through their thematic use in preconstructed decks, through Limited format gameplay that necessarily highlights the mechanics, and through playing with others who are using the new mechanics a lot because of novelty. So the keywords are common parlance, but only temporarily. The sets rotate out of Standard and the old mechanics get replaced with new ones. Because the keywords aren't obvious and players have to memorize their meanings in order to use the cards, this introduces huge complexity creep. The sets maligned for their complexity, such as the ones in Time Spiral Block, had adequate reminder text pretty much everywhere you'd expect it. But the new solution seems to be more along the lines of not giving any reminders, but making players learn a small number of new mechanics for each set, and then they can forget them once the sets are out of Standard, because only Standard matters. Instead of the game getting more complex, everything just resets. It's a brand new game. But some day, probably not soon, but eventually, they're going to make a total flop. They did it before with Kamigawa Block (or with Homelands, for that matter). They've learned for their mistakes, but even being diligent, they're going to mess up again at some point. And if they've pushed so hard to focus on rotating formats and driven all of their past successes to the fringe, that one failure is going to hurt badly.
Anyway, Archfiend of Ifnir looks pretty cool. If that "whenever you cycle or discard another card" mechanic, which is very cool and doesn't need a keyword, shows up more, I'll be sorely tempted to break out the old Fluctuators...