I don't believe it does, I'm seeing the same numbers after levelling as I was seeing earlier.
My guess is that it doesn't add a flat value to your end stats but instead adds to your basic ones in which case things like Mood are applied on top of it, which explains the difference in gains from person to person
This post was last edited by 102***@facebook at 2016-10-17 15:28

I generally don't like upgrading anything if there's no event for it running. If you like the discounts you can grab the threads and save them till there's one I suppose. But a 40% discount is good, the packs they released last BA progression event were much worse.