I don't know if the drop rates are worse now, my sample size is way too small to even guess.

My personal experience was really bad this time, it's day 12 and I just got the second girl from the bosses. Hildr took forever. You really lose tons of money this way, since you can't farm the better paying options. Since upgrading is getting more and more expensive, you need more books now too, farming these low level bosses really sucks.