So what are pros and cons of stock Android.
1. It is unpolluted raw version of Android some people refer to it as Pure Android Experience.
2. You will receive automatic updates in the Android OS from Google.
3. It may be faster than customized OS.
4. Stock Android is very popular with android development community for App development.
1. Sometimes manufactures do really cool customizations on Android all are lost.
2. Some manufactures integrate Android experience with the advance hardware capabilities in the smartphone all of them are lost.
3. Stock Android even though fast in performance may not look very appealing to many users.
So the biggest question is it worth buying stock Android devices?
Well answer is a Yes and No. Based on what will be your preference. The biggest USP of stock Android is that auto updates periodically and you may find really cool performance fixes in future where as in non stock Android the process is very slow and rare as its manufacturer dependent.