Just did some quick math:
I currently have 245 max stamina and it takes 6100 EXP to level (level 66). If I spent all my stamina running ?-4 and used 1 gem to refresh, I'd be able to run the stage 12 times, with 10 energy leftover. Using the 3 gathers, I could get at least 1 more run. 13 runs of the stage would give me 6500 exp, ~10400 seeds, a good amount of gifts/gold, and level me up. Until the I hit a level where the exp needed/max stamina ratio gets too high or I hit really unlucky gathers, I can basically do this as long as I want. Also, as I level up I'll be getting in more runs of the stage per gem, since my max stamina will also go up.

5 gems spent this way would give me about 52,000+ seeds, giving me a good chance for a 4-star (or even 2-3 given the odds), as well as lots of other side benefits like gifts/gold and the extra prizes from 15 gathers. This is worse at lower levels when each gem refills less stamina, but at lower levels you can often level without even spending a gem since the stamina you gain from gather has a larger impact. This is even better at higher levels (assuming you can still level by spending 1 gem) because of the higher max stamina pool.

Not saying that you should blow your gems this way, and this is using an event stage that won't always be here as an example, but it's something to think about. Currently, if you're rolling premium the only winning rolls are 5/6 stars, everything else is pretty much a losing prize.

Originally Posted by Lied

I'm convinced the free gacha is the way to go. I've lost count of how many seeds I have poured into it, but I've gotten 7 4-star girls from it so far. Instead of pulling the premium gacha again, I've been using my gems (efficiently) to restore stamina while farming, which has let me level my team, get gold, get player levels (which makes restoring stamina even better), and get lots of seeds which occasionally gets me a 4 star girl.

I'd probably get more 4 star girls per seed from the premium gacha, but then I'd be spread really thin on resources trying to level/evolve/max affection them all. The way I'm doing it now, I only have a few girls to focus on, so when I do happen to pull a new 4 star girl I have lots of stocked manyus and gifts to immediately get her up to speed. It also lets me actually play the game instead of running a few maps and then leaving for a few hours.

Premium gacha seem like it's more for:
1. First 50 pull to get you started with some 4 star+ girls
2. Shortcut for people with money to burn
3. Only way to get 5/6 stars (which is sadly why I'll eventually need to pull it again once I can't improve my current girls anymore)

But for 4-star girls, free gacha feels to be the way to go as long as you're patient.

Free gacha is probably the real way to go. I patiently saved up 100 stones and didn't get any 5* from premium. In fact, I rolled 19 3* and 3 4*. Then I tried money just in case that was pure bad luck and it got even worse at an 11 roll of all 3*. I'm saving the rest of the $50 purchase to use for other gameplay.
Free gacha at least doesn't disappoint so hard for such a high cost, since you're not expecting anything beyond solid, usable units that WILL get you very far. The 5*+ are not only unnecessary to actually advancing, but are also not even existent in Nutaku's lie of a premium gacha and WILL sorely disappoint anybody hoping for that kind of premium content.

With all this pent up demand for golds Nutaku will probably rake in cash if they put waifus up for sale.

42k roll
one 4* girl...at least got something. ima try 60k next time.

There are people who rolls more than 150k (me) and gets nothing while you dont approve getting a 4* from 42k...

Normal gacha is kind to me:

I was just trying to clear my seeds today and did a 5 roll

->Open Spoiler<-

Best roll I've had (earlier this week)

->Open Spoiler<-

I'm up to 8 4-stars from the free gacha so far. No idea how many seeds I've used though (it's a lot).

Originally Posted by Lied

Normal gacha is kind to me:

I was just trying to clear my seeds today and did a 5 roll

->Open Spoiler<-

Best roll I've had (earlier this week)

->Open Spoiler<-

I'm up to 8 4-stars from the free gacha so far. No idea how many seeds I've used though (it's a lot).

Would really like to get Cepha. Statwise she seems to be the best 4* all around.

Looks like normal gacha also gives you these.

->Open Spoiler<-

Yup they gib them too. I play the game since it started and got none though.

The rates on those must be crazy low....I haven't seen one pop out yet either. At least they show up a lot more often in map 12.

->Open Spoiler<-