Cintiq v iPad v Intuos
I have the 13" Cintiq. Don't obsess about screen resolution - it's just techy nonsense for those who like to read the brochure rather than do any artwork. I find the lag and the need to reset periodically more of a nuisance, plus the power brick and cables which make an already overcrowded desk a snake pit.
I'm also not thrilled at staring into a computer screen all the time I draw, which can be tiring (but others may have different experience).
For these reasons, I still use the Intuos more. After 12 years of using a Wacom, the draw-here-look-there thing is second nature (it felt natural after 30 minutes, tbh).
The iPad looks very interesting, especially after seeing the way Hockney and others use it (search YouTube for demo examples). It doesn't overcome the screen glare but it gets rid of the cables. I just need a way of getting the final drawing off the iPad once it is finished which doesn't necessarily involve wireless or another computer. Never mind HD, retina displays etc - I'll settle for a USB socket on the iPad 3.