I'd agree, currently I have a 4x5 for home use because I can use it instead of my mouse (same size as a mouse mat). Problem is I'm constantly getting frustrated by the lack of room with it.
Remember that unlike a mouse, you can't simply pick it up and move yourself into a better position .. the tablet area = screen area. So you often end up in odd (and sometime painful) positions just to finish an area without loosing your pressure.
I'd say the Watcom, does certainly have the best Pressure Sensor from any other tablet in it's range; but personally I prefer the pen on the slightly more expensive Genius Ranges. They fit to your hand better, also powerwise they use less.. I found this out before ending up splashing out on a new 430watt PSU as it'd reboot my system each time I connected it with my Scanner.
Watcom generally have the best tablets on the market, and for the pricerange they usually are pretty good. I'd also recommend checking out the equal Genius though as they have been producing quite good tablets too.
Generally speaking, for Sketching I still use paper&pencil at home.. at work I used an Watcom3 with Alias Sketchbook Pro.
Sketching / Concepts : Alias Sketchbook Pro
General Art Needs (Texturing) : Adobe Photoshop CS
Digital Art (Painting) : Corel Painter 8/9