I think our different impressions regarding responsiveness is rooted in Alien Dalvik again. Afair you are not using it?
I am running whatsapp, skype, threema, googleplay + services and sailfish "Situations" firing up 3 native apps when detecting my local wifi on startup and activated background services for all.

Boot time stayed the same i think but after the homescreen has loaded the device is more responsive while loading up all that stuff.
I had times when my jolla was unresponsive for 1-2 minutes when google play decides to update many apps.

Now, after first reboot on Aurajoki, google play again updated 11 apps but i could meanwhile start all the apps you can see in the screenshot.
So i am left with the impression that dalvik has been optimized to be more "nice" (process priority wise?).

Could you elaborate a bit on what is less responsive for you, really interesting.