Emergency Aid and Logical Reasoning seem like good benchmarks for healing events. They both cost 2 resources, and they both heal for 2. Meditative Trance has the same printed cost, but will only heal for 2 if both of your arcane slots are filled, which in the end costs more resources, cards, and actions. In a vacuum, definitely not worth it.
Of course, you're not filling your arcane slots purely for the sake of getting this card online--arcane assets do useful things too, and odds are if you're running this card you're also running Dragon Pole. We run into the same issue here as we do with the staff: cards that depend on other cards being in play to be strong are questionable in their utility and efficiency. However, as a healing card you'll be more likely to play it later on in the game anyhow, at which point hopefully you'll have your slots filled. On the other hand, theoretically if your assets are fully set up that means the game is probably going well, meaning you may not need healing.
In addition to the obvious, there are a few not-so-obvious things that make it even less appealing:
- You can only target yourself. This limitation dramatically nerfs the usability in comparison to other healing effects.
- Despite being a event, Meditative Trance is not a Spell. There are several interactions which may be taken for granted that simply don't work with this card.
- Unlike Emergency Aid and Logical Reasoning, the healing itself is flexible! This somewhat makes up for the fact that you can only play it on yourself. Maybe you can run it with Solemn Vow and such.
- Breaking the limits and having more than 2 arcane slots filled takes you into value town. Even just having 3 (from the additional slot you get with Dragon Pole) is pretty good. I'd caution against just taking a bunch of cards that increase your slots, but like the pole if you push it, the effect becomes massively strong (albeit increasingly impractical). I'd probably stop at 5, but if you want to make a deck that allows you to heal 11 damage/horror at once, no one is stopping you.
- Lack of the Spell trait locks out some good combos, but Insight and Spirit have some okay stuff going on! De Vermis Mysteriis and Prophetic still work, Crafty and Boxing Gloves are there I guess, Calvin Wright can take it but shouldn't, Cryptic Grimoire and Eidetic Memory might be good.
Overall, I'd say this card is only worth considering if you're building a Dragon Pole deck and really chugging your arcane slots accordingly. I'd still like to see more support for this deck archetype as it doesn't really seem all that practical especially at higher XP level play, it's just such a cool effect that as of now takes too long to set up and has fairly meager returns for its considerable expenses.