As a web developer, the iPad kicks ass for getting work done.. actually *replacing* my laptop for many things: reviewing online (or offline) documentation, checking email, and oh.. testing my work via Safari Mobile.
That is not being productive... Everything you listed is surfing the web (and checking email). Yes you are right, the iPad excels at that. But even that has its drawbacks as far as being productive in even it's area of expertise. For example, I am replying to you on my iPad right now... It is literally taking me 3x as long to do so simply due to the fact the keyboard is so horrible. So even in the things it's designed for, iOS still hobbles any productivity you might be able to get out of it. Android at least has the Swype keyboard, which helps some.
If your work IS the web, the iPad rocks.
I am going to guess by that statement that you aren't terribly fast or efficient then to start with. My work is IS, among other things, and the iPad (nor any of my Android devices) increase productivity by any cost effective amount.
In a pinch, I could code on it using a bluetooth keyboard, but that's not really what it is best at obviously.
At the very least, it makes a hell of second or third monitor (and has a much better display than the standard 75DPI used on most desktop and laptop displays).
I do have some serious gripes, primarily that of depending on iTunes to sync everything (but I get around that well enough with an old Linksys NAS200 stuffed with 2Tb in drives, a TZO.COM dynamic dns account, and port forwarding on my home router).
I actually held off on an iPad until the Samsung Galaxy reviews came out... I only use Linux at home and work, and a droid for my phone... I -really- wanted my platform to be a droid. My last "Internet tablet" was a Nokia N800 running Maemo... a pity that Nokia smothered their tablet line and moved the OS goalposts so many times (even now, the n800 is impressive... but lacks newer software).
Maybe in a couple of hardware revisions, android tablets will get there. I'm sure of it. But right now Android is not designed for tablets, and people are trying to force it into that hardware...
No, Android isn't there yet either, sadly. But the open development nature of it means it will likely get there sooner rather than later, whereas iOS was not built for it, can not do it currently and likely will fall farther and farther behind. Again, this is probably fine with Apple, since they aren't about being productive with iOS, but about providing an expensive walled garden.