Came over from that "ice cream flavour" thread which is specifically about OmniOutliner on non-iPad iOS devices (iPhone and iPod touch). I'll go back to that one in terms of "mobile outlining." But I thought I'd share some my thoughts about my own usage pattern. Who knows, maybe it'll help the Omni Group make sense of how the Mac OS X, iPad, and other versions of their products could fit together..
It does sound like we're all different. Which is what is so great about being human. (I'm an anthropologist.) It does make it more difficult to apply cookie-cutter solutions, though. Yet, we need not focus on these.
The relevant devices I have are as follows: old Mac mini, iPad WiFi+3G, and 4th generation iPod touch. No smartphone, no laptop/netbook, no dedicated eReader..
At this point, I don't feel anything's really missing, in terms of major pieces of hardware. For instance, I don't miss using a MacBook. And I do use all of these devices everyday, as part of my workflow. I use desktop software much less frequently than before. A lot of what I use goes through Chrome on my desktop and through apps on my iOS devices. It's where I do my backups and archives, but it's more of a hub than a central focus.
My iPod touch is used for a number of things which are mostly very short "spurts" of work: working with notifications on email or social media (sending quick replies), looking up simple information (dedicated apps or Safari), quick notetaking (in TaskPaper), etc. I also listen to a lot of podcasts on my 'touch and may play the occasional casual game on it, especially while I'm doing something else (like listening to a podcast).
My iPad is mostly for "mobile work sessions." As such, it is for me a key productivity tool. Some Omni software could have helped, if they had come up with their full lineup more quickly and with more emphasis on "the cloud." But I have most of what I need from relatively simple, focused apps.
For instance, the iPad finally allowed me to get my workflow together in terms of RSS. Reeder makes it comfortable to quickly select things "to read later" from my Google Reader account (both subscribed feeds and people I follow). Those selected pieces go to InstaPaper, which is very comfortable to use with even rather long texts, on the iPad. I also put a lot of things in GoodReader, including all the required readings for my courses. I also create simple slides in Keynote while commuting. Not to mention that the iPad's my tool of choice for liveblogging.
With all of these things, the iPad actually fits more than a laptop or netbook, for me. And the connection with my iPod touch is quite important. For instance, TaskPaper on my iPod touch is for my "geistesblitz/braindump" while TaskPaper on the iPad allows me to do extended work with these notes. Sure, I can do much of the same thing on my iPod touch, but it's much less comfortable and efficient. Without the kind of seamless synching allowed by TaskPaper and SimpleText.ws, my life would be significantly harder in this respect.
My two iOS devices fit together both in terms of synching data and in a special kind of multitasking. For instance, while I'm reading an academic text on the iPad using GoodReader, I might take notes on the iPod touch in TaskPaper. (GoodReader recently added annotations, and I might use that, but I need to repurpose my notes into outlines or linear text.) In that sense, the two together allow me to have very productive "mobile work sessions." In a much more flexible way than with a MacBook.
And that's the second part of the equation, for me. A significant shift in my workflow.
The concept of a "work session" is probably ingrained in the way we do things, but the shift to mobile computing is still unfolding. The iPad allows me to work in a very different way from before (when I was using a MacBook, iBook, or PowerBook). It's a step further in making the "work session" less constrained.
With a desktop, you "sit down at your desk to do some work for this specified amout of time." Sure, you can do different things during that time and it might not be so focused or so obvious in terms of the time you spend there. But it's still something of a "scheduled" thing. There's a clear structure.
With a laptop/netbook, you have a bit more freedom. For instance, you can make more physical places into workspaces (cafés, libraries, plane seat). In that sense, just the fact that you don't need to be at your desk means that you have more flexibility in your schedule.
But the idea still is that you set yourself up, you start working, and you end your work session with some closing routine. While the time it takes to turn your laptop/netbook on or off may not seem so significant, it tends to change things in quite significant ways. Though you technically could be (and might end up, in a pinch) working on your netbook/laptop for a five minute "quickie," chances are that you'll mostly work on such a device for a minimum of twenty minutes or so. Haven't done (or looked for) research on this, but there's anecdotal evidence for this. It's not the difference between five and twenty minutes which matters, here. It's the "should I take my laptop out when I'm waiting for my meal?" kind of situation. These can add up quickly in terms of time but it also goes the other way around. There's a special kind of freedom associated with being able to choose on the spot, if you can go either way.
With a handheld device, you could eventually do a short "work session." In my experience, though, a handheld device (iPod touch, cellphone, PDA..) is either for short tasks or for more extended things which don't require much focus on the device. Though you could technically sit down and work from your iPhone, it's just not that comfortable doing so, in most places.
With the iPad, you get a comfortable device for extended work sessions with the benefits of an instant-on, hands-on, hold-on device. You can indeed sit down and start working on your iPad as you would with a laptop or netbook. But you could also whip up the iPad for an impromptu work session while you're commuting. You can do a few things while standing and sit down later to work more comfortably, without much of a transition. It's not an issue if you have to quickly get up and leave since you can carry the iPad as-is (as long as you have a case). More than with netbooks/laptops, you're likely to get your iPad out even if it's just for five minutes. Unlike what people tend to do with handhelds, it can really be a full-on work session, even if it started with something simple.
The specificity of this isn't about what's technical possible with a device or what the device is meant to be, In the study of material culture, we talk about "affordances" which, roughly speaking, correspond to uses suggested by an object. As such, it includes extended possibilities for an object to be used in flexible ways, depending on context. You could technically use an iPhone for an extended work session and you could use a 17" latop for a very short one. But a tablet is rather unique in "affording" both, in a significant way.
The key there, though, is that all usage patterns matter. Focusing on a specific set of usage patterns seems to be an inappropriate strategy in most cases, these days. Not that you can't have an app which does a lot of different things. But trying to predict what people want to do is mostly a way to stop innovation, not to make it grow.