Dang, missed this reply somehow! Thanks for going a bit in depth on thisWhat do you think of the iOS keyboard? To me, when I owned the 4/4S, the keyboard felt like it couldn't keep up with how fast I thumb. It would (and still does on my iPad 3rd Gen) often miss keys, give me back ridiculous autocorrections, and the fact that there's no control over what words the dictionary saves really made the typing experience (and thus the email/texting messaging, googling experience, and anything else requiring typing) pretty dreadful.
The reason I find the stock Android keyboard (I actually prefer ICS over JB, but I'll explain more on this in a sec...) better is because it's far more responsive. I barely experience any missed keys. Also, the ability to decide what words the dictionary remembers and doesn't remember adds so much to the typing experience. The suggestion bar too is a blessing.
Editing is a bit of a toss up. On the one hand, I like how iOS snaps certain words, sentences and even paragraphs when I'm highlighting. On the other hand, I find "micro-editing" easier with the cursor that Android offers.
The one thing, and only one thing, that iOS keyboard does better than the stock Android keyboard is shortcuts. Google really missed the point of shortcuts in JB because instead of automatically changing your shortcut to the desired phrase, it offers it up in the suggestion bar, which adds an additional step having to pick the desired phrase. Kind of defeats the purpose of the shortcut.
Plus, I haven't even opened up the discussion to the plethora of other third party keyboards that are out there that offer some amazing alternatives (Swype, I especially love for one hand use).
Having said all that, I think Google really took a step back with the Jelly Bean keyboard. Strangely, it's become more like the iOS keyboard (but it's still better). I've noticed it misses keys more often, and misses autocorrections every now and then (for example: I should never ever see the word "tge" unless I've actively chosen it from the suggestion bar. "Tge" should autocorrect to "the" all the time, and it usually does, but every now and then, it shows up in my messages. It's as if the OS missed it or forgot to correct it. This happens with other words too every now and then, and it never did this in ICS; I don't know why it does it in JB, and I'm hoping a patch will remedy this in the future). Also, backspacing isn't smooth on JB anymore, whereas it was super smooth to backspace on ICS. I'm really not sure what exactly happened, but Google definitely changed or rewrote the algorithms or data/code or something for the JB keyboard and somehow made it clunkier, slower and less reliable.
It was near perfect on ICS. : shrug :
However, JB or ICS keyboard is still leagues better than iOS'.
That's been my experience, and like you, I'm a big big keyboard guy. If you dig up my old old posts on this forum and on the XDA forums, that was almost all I ever talked about.
And while I think there's something fundamentally wrong with the iOS keyboard software-wise (because the same issues happen when typing on my iPad's larger screen), the extra real estate is a nice plus on the GN.
Good luck.
I do think the iOS keyboard is rather annoying. It's confusing because the touch responsiveness of the phone/OS in itself is so crisp, so typing on my 4s always feels like such a breeze the first few seconds, but then somehow I always end up going back and doing a lot of manual corrections. And the accumulation of saved misspellings over time drive me crazy.
Editing/selecting text, and shortcuts I agree are very good on iOS, I'll definitely miss those if I go Android.
The issues you mention with JB sound like something they'll hopefully be dealing with ASAP, given how important the keyboard experience is. Otherwise getting the ICS keyboard from the Play Store sounded like a good option (thanks blackhand1001 for that tip). Did you try it yet?
All in all, I'm 99,9% decided to go Android for my phone now. A huge factor is after all the ability to get a much bigger screen than with the iPhone - that alone should improve the typing experience quite a bit. Currently having wet dreams about the Galaxy Note 2, or even better a Nexus Note......