Bloodsport - welcome to the "real world" where one doesnt get multple gold/rainbow filled rolls straight from the get go. Makes you actually use the low tier girl for a time.
Thoug in DMM its super easy to get the Event girls, so those will fill your ranks rather quickly.
As for the pulls - it is what it is, my first 4 rolls were horrid shit. Then bam 3 new gold and 1 rainbow. Since then its been mostly shit again
But with the amount of Flower Gems, where I can pull once/twice a month it doesnt really bother me as much.

As for the equipment - the High tier grade rolsl have only one purpose - to get a special item that gives the girl who equips it some weak boost in the form of an ability rather than just the usual stats. I have two of those so far, but ultimately its not worth to roll for it.
It seems to me like the High tier equipment has diminishing returns when turned into Bonding Crystals, which in turn exchange for Danchou coins.
I´ll just keep spamming the mid tier equipment gacha to get as much Bonding crystals out of it as possible. Currently sitting at 51 Danchou coins and would like to get the 60D ticket before the shop resets.