I have just upgraded to Emacs 25 (windows 32-bit version on Windows 10), and found out that there are still quite a few things to smooth out. One includes potentially the PNG background not being transparent. On Emacs 25: On Emacs 24: Or is it just me due to my settings? By the way they're using the same .emacs init file.
Oh, also my Emacs 24 starts in about 5 seconds, while the new Emacs 25 takes about 8 seconds.
Hope there can be some tips from members here. Thanks in advance.