Lola's had a similar thing when it came out, depending on how far you progressed you got bonus diamonds in the first month.
I personally don't mind the spy cams and only having 2 active. Cherry's is such a drag anyway, I'm into room 3 and it's so slow.
I think the new permanent game has more issues. The fact that old girls generate energy as well means they're progressively making things harder (Carol vs Mistlehoe). I find with the event girls you have to focus on them straight away. The new girl Adriana seems alright, but it's very spin dependant. Having to waste time when you don't get right items sucks. I haven't gotten a single item for Adriana, so I'm not really sure I'll be able to finish her without spending diamonds (I also didn't finish Molly so lacking her energy income).