Wacom style devices are extremely affordable. I have a $30 drawing tablet which I use for digital art and works very well.

The most expensive part of having tablet input is the real estate square footage required for a larger desk to accommodate it.

Which is not larger than a mouse pad.

Tablets need extra space only when replacing the embedded touchpads or trackpoints of laptops.

For someone who uses a desktop or who prefers mice to touchpads, a tablet does not need any extra space, it just replaces the mouse and the mouse pad with the stylus and the tablet.

There are big tablets too, but for replacing a mouse and for simple drawings a small tablet like Wacom Intuos S is perfect.

Mine is about the size if a greeting card

I have one, and flipping it from "laptop mode" to "tablet mode" adds noticeable friction, especially if you have e.g. a dock connected. Then again, so does having to carry around a tablet.

For an office job I'd take the external tablet, since my laptop would likely be plugged in all the time.

You could also keep it permanently in tablet mode and use an external monitor, mouse, and keyboard. Just don't underestimate the mode change.

Tablet laptops usually carry:

* only glossy screens

* screen with touch layer look worse than non-touch counterparts

* poor to very poor software support

Not to mention the hefty price tag.

I have a 15" HP Spectre X360 and it looks good and has great software support imo. Glossy screen, nbd..

Tablets tends to emit heat, leaves fingerprint, your hand obscures writing, and expensive. Upside is it's more conceptually straightforward. To each their own.