Difficulties of combining customizations in the same place. Typically customizing Android to adopt something you like in one versions of Android requires you to give up what you like in another version. In contrast to jailbroken iPhone where such limitations do not exist.
Multilanguage support. I can combine any languages in iPhone. Not so with Android where a separate firmware is issued for each region.
Inconsistent UI. The copy and paste of SGS 2 in the browser and that in the other places are designed differently. If you install third party software such as dictionary.com and skyfire you see different design again.
KIES. This is a terrible piece of unreliable software.
Pink patche on photos taken which are very obvious on while background.
