Feel free to share your experiences.
Bought my first pack ever (New Bloods) and got a Chiara. Levelled it to max and sold it for a decent 3.6k, which made me really happy as I was expecting whatever I found to be worth less than 1k. The other two cards were Archibald and Lin Bee, which I kept for my deck and collection respectively.
I have also the same feeling that rainbow is the best.
I tried 4 full decks, but only found 1 junk rare card from each pack. Then I switched to rainbow and got 3 rares from 4 packs. This is even better than my previous experience with Danger pack, which is about 1 rare every two tries.
Now I really believe the dev has tweaked the odds and you could expect rainbow to yield better outcomes.