Wacom Cintiq / Pen Tablet Advice

Calling all Wacom tablet / Cintiq users....

I'm looking for your advice / opinions. I've been using a Wacom tablet for the past 20 yrs or so. I started with the original Intuos and now its time to buy my third one. I'm trying to decide between an Intuos Pro medium vs the Cintiq Pro 13. I've never used a pen display, so not sure Ill like it. Its an expensive purchase  if I don't like it.

I'm currently using 3  24" monitors. I'd hope to keep using all three along with the Cintiq. One question is how do I access my other three monitors from the Cintiq? When using a Pen tablet it is mapped to cover all three monitors. I keep all my photoshop pallets on my left monitor and work on the image on my middle monitor. With a Cintiqe am I able to map it to cover all three monitors? Or am I now limited to just the space on the Cintiq? Do I need to put all my pallets and editing window in photoshop all on the Cintiq. So basically am I forced to do all my work on a smaller 13" screen? I'm trying to understand how this all works when using a pen display vs a tablet.

Any other advice and opinions is appreciated. 

JeffN