Hi all, just adding my two cents:

Instead of a tablet or mouse, I moved on to a Surface Pro computer with touch screen and pen. It's super mobile and super versatile. I can use it with the type cover (handy for Photoshop shortcuts) wherever I have access to a table, flip the type cover to the back and work with the screen only when I'm on the train in full morning rush, or when I'm home I can hook it up to a second monitor, I use it just like a Wacom tablet.

I used to work with a Wacom Bamboo in the past and I would still highly recommend it (especially considering the price compared to a full touch screen laptop!), but in the rush-and-bustle circumstances I tend to work on my maps, my current setup is just perfect