I had the xreas system in my ’05 4R Ltd/V8. One cross system line developed a leak from rust rendering it inoperative. Replacement components from the dealership were very pricey as noted by other members. To the best of my knowledge, no aftermarket replacement units were/are available. The OEM system is pressurized and
DYI installation can be difficult to ensure no pressure loss during the install.
I replaced the entire system with regular shocks, reusing the front springs which fitted nicely. The xreas OEM shocks cannot be reused.
If you also have the air suspension option, like mine, I’ll suggest you keep it ( if its still operational ). I kept mine. I believe the ride quality is better ( vs springs).
If you decide to junk the air suspension, you’ll have to remove the two air bladders over the rear axle and replace them with a pair of springs ( replacement kits available from auto parts stores ).
Yes, there was a slight leaning of the vehicle when rounding corners when compared with the xreas suspension, but not enough to be off putting IMO. Also depends on what shocks one decided to use. Bilsteins are popular and also $$.