Ok. First off, I have no intention of replacing my laptop with my iPad. It just turns out my ( brand new! ) Macbook pro is DOA with what looks like a bad hard drive, which has left me no choice but to try to use the iPad for my everyday work. Here are the things that make that difficult, if not impossible. Some are certainly addressable, some not so much, at least not obviously.
1. Email filters don’t work, or don’t migrate at least. All the filters I have set up to separate mailing list messages from messages I NEED to read don’t function, or haven’t come over via .Mac (trial) so everything ends up in the inbox
2. Email search doesn’t work beyond a certain point. If it’s not in the first 50 messages then you can click “search on the server” aka wait, wait, wait…
3. I can’t see two things at the at same time. Want to take information from a spreadsheet and put it into a web application, or reference a document to write an email? Not going to happen.
4. Typing on screen works, but, for me at least, there are too many errors to not make it somewhat grueling. There’s an evident solution for this one – get a keyboard.
5. The obvious – some applications aren’t all that useable for what you need to do or don’t exist. I do a lot of my work in Fireworks designing mockups or final software graphics. Can’t easily do this with the existing software and not sure I’ll ever be able to do it with my fingers.
All in all, I have been pleasantly surprised by how useful the iPad is in a pinch, and that some of my biggest issues could probably be resolved by Apple without too much difficulty. The portability is great – definitely preferable to carrying a laptop everywhere. If your job consists of a lot of email, meetings, and document writing and review, it’s a pretty serviceable alternative. Once you need to do some more complicated work, like programming or graphic design, it’s not so much of a solution, at least not now, for my work ( software design ).
So the good news is it can do work in a bind. I wouldn’t buy it for this purpose, but it’s a plus. For me, the killer app is Instapaper, if you have a commute where you can read, but having a laptop backup is gravy.

