If you get a slow phone after updating I suggest you do a factory reset on your phone. Actually, I would recommend that every time you upgrade to a new Android version, just as I would recommend formatting your disk when upgrading to a new Windows on your PC.
My JP6 was very fast (threw in the Voodoo fix anyway and now it's just flying away) and everything works as it should, except one thing. My battery consumption has increased a lot, which mainly seems to be that the sceen is much more power hungry now. I won't be able to go two days with everything on and medium usage as I used to so hopefully they can fix this.