Originally Posted by Tenhou

Third tier has a chance of giving 4 chests and always 3. All 4 chests has a chance to contain lvl 100 and will at the very least contain lvl 20s.

First tier wins early on since you level fast enough with its exp efficiency. Thus you can farm more manyus in total. However, later on you will take so long time that it is no longer very efficient and thus the third tier garden wins since it gives a great deal of exp and you want to farm the 12-? maps for a chance at ampys.

Thanks for correction. I was basing my third tier calculations on daily map in previous post.
This brings tier 3 to 7,5 - 26,8 per map (that is, 7,5 / 11,7 / 15,9 / 20,1 / 10 / 14,2 / 18,4 / 22,6 / 26,8 per, depending on drops, with 16,4 arithmetic average) and 37,5 - 134 per 400 stamina (with ~81 arithmetic average). This does seem more like it)
Of course, here I didn't count the cost to run 12-? maps themselves, put other tings outweight them, it seems.