I just got my Icon Stage 6 installed. Came from the stock LE XREAS suspension.
Thoughts: less body roll around the corners and less nose-dive upon hard braking. Because the springs are designed to handle more weight, it is a little bouncy right now upon coming to a full stop (back/forth rocking motion), but as the suspension settles and I add the planned weight (shrockworks skids, followed by bumper/winch, dual battery) that will go away.
The UCA's are required to bring your truck back to alignment with the lift. I haven't scanned my sheet yet, but High Tech Auto and Truck did an awesome job on mine.
High speed potholes: Driving on crappy down-town roads daily, my highlift rattles quite a bit. with the Stage 6 I have noticed less rattling, and the truck feels more comfortable running at higher speed over the crappy surfaces.
I'm still running stock size tires and while I will size up when they are worn out, they do not look out of place (although the wife did call them barbie tires when we picked up the truck!).
I'm very happy with the setup. both for the function, the beefier components and the bling factor.
I don't have all my pics uploaded yet, so this picture is all I have to show for it so far.
Warranty issues: your warranty is only affected for the modified parts/systems. i.e. an engine warranty issue is not declined because you have aftermarket suspension. don't expect Toyota to pay for Icon "warranty" work though.
Okki