I also had the feeling, that the contrast was not as good as with 2.4.
Also ghosting seemed more severe.
But since I have "ultimate ghosting" (page never gets cleared anymore) now (I got my ticket number, see here:
https://www.mobileread.com/forums/sho...?t=7068&page=2 )
I dont know, whether my display just showed "rapid ageing".
But it could be a bug introduced in 2.5, maybe my "ultimate ghosting" can also just be fixed by 2.6 . Could be that the driver is "hung in some state".
Well, well, ....