How many 4.2 devices do you own? I'm guessing 0.
I'm also guessing thats the amount of Android devices you own.
Want to know how many 4.2 devices I have? 3 ... and 0 of these have "all kinds of glitches".
Furthermore, I'm almost certain that by "all kinds of glitches" you mean the lag caused by Google Currents (which
isn't a core App of Android) which can be fixed in under a minute even by a complete novice user:
http://www.talkandroid.com/141899-does-your-nexus-7-lag-after-the-4-2-update-theres-a-fix-for-that/
Oh, and I believe that's since been fixed in an update.
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Because all the iPhone users tell the world that benchmarks mean nothing when Androids gets better results.
Here's how it works:
When an Android device gets better benchmarks, they don't mean anything and benchmarks are meaningless. It's all about the user experience.
When iPhone gets better benchmarks, UX is meaningless and any phone that doesn't beat iPhone in benchmarks (which are now vitally important) is total garbage.
You know. The same way that after iPhone got the "retina" display, any phone without it had a completely unreadable screen. Then, once all the Android devices started getting this technology it was "sure they have a high PPI but the colors aren't as good".
Then iPad Mini came with a non-retina display and suddenly everyones vision deteriorated and they "couldn't tell the difference" or "the screen is perfectly adequate".