To be honest, I haven’t even been able to make a tablet really work for me as a serious laptop replacement for any halfway serious office productivity work. Except for a very short trip I bring a laptop because otherwise I’ll run into something I have trouble doing that I need to do.

True, but i feel the same way about laptops. For true productivity i need at least one big display, so will usually dock it with an external display, keyboard and mouse. Funny thing is that the modern iPads connected to an external display gives more or less the same experience as a laptop (as long as you're not programming...)

I have a multi-display desktop. I accept I’m not going to have full capabilities if I’m not at home. For travel an external display on an iPad is a nonstarter.

But then you need a table or some sort of surface to put the keyboard on, and then I might as well use my laptop if I have it. I want better editing for when I'm standing in line at the grocery store with one hand free.

I have a keyboard that I've attached a guitar strap to, in order to be able to type while standing, without a table to rest the keyboard on.

You reinvented...the keytar.

I miss the Sidekick, myself. Was the perfect device for writing while standing. Physical keyboard and a big-ish screen, with the form of a modern smartphone.

The swivel design made finding a decent case tough though. And there were few apps.

Which was an influence on the first Android device, the HTC Dream. Swivel keyboard AND a trackball. It was pretty cool but unfortunately didn't catch on.