I actually think there's a lot of variation on peoples estimations of brakes on the XR, some people seem to think they're pretty good, others dislike them.

Personally, coming from owning Capris most of the time before the Xr4x4, I think they are pretty good in standard form.

As far as the original post goes about improving the braking, i'd guess that the dax rush is a fair bit lighter than the xr, and possibly just aftermarket brkae disks would be the cheapest solution, but i'd agree with Doh and swap the hubs over as then any cossie combination is then possible