I quickly dug up some coefficients for existing spells similar to riptide (might contain mistakes):

Regrowth: 98.7%
Moonfire: 67.1%
Immolate: 85%
Pyroblast: 135%

I'd expect riptide to settle around 87% (add 1.88 from spell power of cours) which is what 15-second duration moonfire has but of course it could end up as a step down from immolate also at around 80% or something entirely different.

I finally realized why riptide numbers look so odd.
Riptide work now this way:
Direct = [base value + (cast time /3.5) * 1.88 * 0.5 *spell power] * talents * buffs.
Hot = [base value + (hot time / 15)* 1.88 * 0.5 * spell power] * talents * buffs.

Regrowth work exactly same way. So these might be final numbers. But this spell might be added to many talents and then get some additional benefits. Now this not look very good 51 pointer but you can say same about any 51 pointer what shaman have get.


Negg: Coef is divided to instant and hot part. Both get only half of what spell get without other part. Regrowth work just like that. Look that formula above it match every in-game test. Problem is why healing spell get this penalty but damage spells work differently. Just look at flame shock numbers.

My problem with the 40% coefficient is simple, atm an instant heals gets 43% of your + healing, as +healing will be almost cut into half for the spellpower change all coefficients for healing spells are being increased (*1.8) to get the same net result.

So how can Riptide have a 40% coefficients as posted by a blue then ? Doesnt make sence to me. The minimum coefficient should be 78% for instant healing spells.

And doesn't the initial part of riptide atm work like this: Direct = [base value + (cast time /3.5) *spell power] * talents * buffs.
Where it should be: Direct = [base value + (cast time /3.5) * 1.88 *spell power] * talents * buffs

I'm pretty sure they've forgotten the 1.88 multiplier off some spells (such as Riptide and Wild Growth). Would be good to get a blue confirmation, though (or some other explanation on why the 51-pointers have such poor scaling).

EDIT: perhaps not forgotten from riptide but I'd expect it to eventually get a custom coefficient anyway.

Numbers match with 50% penalty but not with missing 1.88 multiplier.


Edit:
Direct = [base value + (cast time /3.5) * 1.88 * 0.5 *spell power] * talents * buffs.
Hot = [base value + (hot time / 15)* 1.88 * 0.5 * spell power] * talents * buffs.

Direct with 1511 spellpower = [795 + (1.5/3.5) * 1.88 * 0.5 * 1511] * 1.1 = 1544
Direct with 1676 spellpower = [795 + (1.5/3.5) * 1.88 * 0.5 * 1676] * 1.1 = 1617
Direct with 1820 spellpower = [795 + (1.5/3.5) * 1.88 * 0.5 * 1820] * 1.1 = 1681
These match with Trifles number ranges.

Hot with 1511 spellpower = [795 + (15 / 15)* 1.88 * 0.5 * 1511] * 1.1 = 2437 or 487 per tick.
Hot with 1676 spellpower = [795 + (15 / 15)* 1.88 * 0.5 * 1676] * 1.1 = 2607 or 521 per tick.
Hot with 1820 spellpower = [759 + (15 / 15)* 1.88 * 0.5 * 1820] * 1.1 = 2756 or 551 per tick.
These match with Trifles numbers perfectly.

So we know scaling formula but we don't know why healing spells get this penalty.

Actually, my numbers were also off.

Spell Healing 0.45
Spell Damage (=spellpower) (All Spells) 0.86

So if all +healing is transfered to spellpower there needs to be a 1,91 mod on each coefficient to get the same neto result.

Problem with that is:
The current Tidal Focus already gives you 25% of your totem's mana cost back when it gets destroyed. Oh, and in addition when it doesn't get destroyed, too.

Effectively what you are proposing is a very heavy nerf to Tidal Focus. Currently it always gives 25% "back", by simply reducing the cost by 25%. If it were to only give 25% back when it gets destroyed, that'd be much weaker.

If we're discussing Arena buffs to shaman, I'd rather have a talent that returns 300%-400% of the totem's cost if it was destroyed. That way, there's a choice for the enemy team: kill the totem, remove a shaman totem buff, and give the shaman some extra mana for healing/DPSing, OR leave the shaman's totem buff up. Totems will never be destroyed in a PvE encounter, so this talent gives some viability to Arena shaman.

Also, make Riptide a Frost school heal. That way, a shaman can heal with at least 1 spell, even if he's locked out of the Nature school of spells.

This would be interesting, but any way you slice it, Riptide is a terribad talent. It needs something for sure.

Although nice to have a fun pvp talent, my main concern lies with pve. Spirit Link was overpowered in the sense that it made resto shamans required in every raid, which is exactly the idea Blizz is trying to remove from raiding. It either had to be nerfed or replaced, having it replaced with something most resto shamans always wanted: a HoT, is great in my book.

From my testing in the PTR I must say the spell looks good in theory, but lacks the scaling. As been said 1.5k-ish direct heal followed by a tiny hot is a little on the low side. My Earthliving proc ticks for just below Riptide which makes little sense for a 51 point talent. This is being looked at last I read blue posts, so I'm confident it will get up to scratch by the time it goes live.

One thing that has come to mind is a new way of healing because of this. Lately I've been dropping Healing Stream over Mana Spring as I usually have a spriest in my group. The amount it can heal is quite substantial and that's just for one group. Seeing as Healing will now affect 25 man and considering the 20% increase glyph, I can see a shaman speccing for raidhealing in a different way. Get the healing glyph, add the +1 target for chain heal and pick up the Earthliving glyph and things can get quite interesting. From what I've read, Earthliving can proc on any of the 4 targets of Chain Heal as well, making it a very nice hps output on the raid.

From what I've seen on PTR, I'm not as impressed with Tidal Waves and Ancestral Awakening. They are fun, but gimmicky and too much of a mana impairment to truly function in a raid imo. Granted, it's on PTR and at 70, so things could change quite quickly. But comparing the chances of proccing Earhtliving with Chain Heal, the new added bonus via Riptide and the mana costs, I have a nagging feeling we'll only be using those Tidal Waves in combination with Tidal Force to keep up tanks in a tight spot.

Koraa just posted this little gem concerning Riptide

Looks pretty good. Glad they added a charge to Tidal Waves.