I can't say I recall any real noticeable issues with iOS 6.0, at least nothing on the level that is being seen with iOS 7.0 (or even 7.1 so far).
The real question is how far is 7.0 from 6.0 compared to 5.0.
It's one thing to add new features every new version but it's another to change the core architecture.
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My intention wasn't to compare 6.1.4 but it came with that so I did. Anyways, even if we compare 6.0, in terms of speed and functionality it is a bit faster. When we had 6.0 we didn't notice but now that we're on 7, it's definitely noticeable. Not do or die, but when you see someone with 6 it's like "Oh man, that's so quick".
That being said I thought I would "miss" iOS 7 but so far nothing yet. Except for the few times I've tried to use control centre.
Oh I know what you're saying. I wasn't pointing fingers at you it's just we see a lot of threads of people comparing iOS 7.0.4 to 6.1.4 and it's really not a fair comparisoin as 7 has not had a few revisions (7.1.X).
Yes, iOS 6.x was fast. No question there. It was also boring and mostly unchanged since the introduction of iOS. my guess is iOS 8 will be much faster than iOS 7.