If you are not playing a playset, or you are playing a sorcery/instant matters style of deck, Impulse is more of a go-to card in this situation. If you are playing a playset, or using it as removal for your attackers, not running this over Impulse is...well, dumb.

Soul of the Harvest is distinctly better. You don't need to rely on things getting killed in order to use it. It's also more of a payout if things do get removed in other ways, like to hand.
Also, Trample. Everything is better with Trample.

Synergizes with blue discard digging. I really don't think less than or equal to is a legit assertion in a vacuum for this card. Even at 3 copies it can enter greater than territory. Whether you choose to run this or Impusle in a deck looking for a 1 CMC burn spell is going to be a context driven decision. It's not in the same realm as Timberland Guide being less than or equal to Obsessive Skinner (where there is never a scenario where the former will be greater than the latter).

Reasoning? I know you are saying this scales up, but it only scales up by casting multiple versions of this exact card. I need to draw and play 2 of these to get to 3 damage. I only need to draw one Fiery Impulse and two of all my other instants to get to 3 damage. Yes, this has a higher ceiling, but that's super late game barring a very specific early draw.

My reasoning is in my last quote.

I don't really like either card, honestly, since as a burn spell it cannot go to the face. But the casting cost is good and the damage scales well. A late-drawn Impulse is ok, but a late-drawn Galvanic can save you from Avacyn or possibly Sylvan Advocate. It just has better upsides throughout the game, whereas Impulse is "meh" to "ok".

But, to each their own.

Both are specific to builds. I'd rather have Fiery Impulse in a deck like Grixis control where I can rely more heavily on other spells to fuel it, whereas I'd rather have Galvanic in a deck with self-mill to force it's usefulness quicker.

But yeah, probably the biggest advantage Fiery Impulse HAD over it is that it existed as good early burn in an era where the other cards were weaker. This is more of a Diablo-esque analysis of DPS than it is an "oh man, I'd much rather have THIS one in my deck" type of thing.

Honestly, they are both overshadowed by better early removal in other colors and the higher density of quality creatures than in the pre-SOI era. Neither are really bad cards, but they have a hard time dealing with most creatures 1 for 1 and you can't throw them at your opponent/opponent's Planeswalkers, which seriously limits their usefulness.

Which is what I'm really waiting for. We desperately need more ways to deal with planeswalkers. Our meta is growing more and more into a planeswalker war, which isn't a good thing I don't think.

Exactly why we would not get it XD

Maybe I'm using fiery impulse wrong, but seems like more often than not the first one is only hitting for 2. I'm typically killing a human or unflipped werewolf T2 or T3 before I've put two other I/S in GY...

I don't think we have enough face burn options in duels to discount this or impulse yet. Yes other colors have better creature removal options, but people are still going to run bounce and burn for the fun of it.

I seriously hope we get both the red and blue X accumulative spells, along with the insect horror wizard generator. Add in some blue discard digging and profit. Fun to build that deck, I think.

Agree with the comments on PW. Hope this set gives us more answers for them. Superfriends is already good, and only getting better with more coming.

Well, if it's t2 or t3, both of them are going for 2. My point is that typically Fiery Impulse will reach 3 quicker than Galvanic, and the fact that Galvanic can hit 4 or 5 super late is relevant, but it's power v. consistency in most cases.

Ironically, the card I'm most excited to get to use is an unbugged Disciple of the Ring. That's the card that Esper needs.

Also, not for nothing, but it's a Wizard for that tribal card.

Where's mjack to tell us how Take Inventory sucks?

How does it suck? And why mjack?

Don't say his name. Haven't you seen Beetlejuice?

Or Harry Potter?

And the B-word has to be said 3 times. So that's 2 now for the M-word...

Back in the Mothership, when Magic 2014 got one of its deck packs, one of the decks included Accumulated Knowledge, and there was a multiple-page discussion about the card, that boiled down to every single person in the subforum telling him the card is great while he alone denied and kept saying it was bad.

How did he think that was bad? I'd LOVE to have Accumulated Knowledge

I don't remember the details. Probably because it was no Moroii...

Ok, I'll stop with the old inside jokes now.

Well, in 2014, it wasn't great. It's a good card, but it was in a Reanimator deck that wasn't especially competitive against the top decks. It's not a bad card, but Accumulated Knowledge was competing against decks dropping T4 Primeval Titan or decks with a full playset of Remand.