I'll try not to repeat anything that has already been explained, but I can offer a "re-world" review of the X-Reas. I test drove an SR-5 without the suspension and it road very nice...very smooth and comfortable. Like a big Caddy almost I didn't push it in the corners at all, but it did have some body lean.
Then I drove a Limited with the X-Reas...what a difference! The ride is a bit firmer, but by no means uncomfortable or jarring. The truck stays perfectly flat in the corners and level while breaking hard. As far as pot holes go, they are everywhere in MA, my Limited goes over them with ease. Very nice, controlled ride.
If you don't plan to modify the suspension for off-roading, then I wouldn't think twice about paying extra for the X-Reas!
Good luck, I hope this helped!