They can be had for less. Keep looking. I love mine as a daily. Solid as a rock, thusfar (knock on wood).
I use mine only in the nastiness. Even in rain, I don't need it. Just really bad snow/slush. It's a nice thing to have.
The only issue mine has is the leaking valve cover gasket. I'm just too lazy to fix right now.
If I recall, later XJ's had "disliked" heads. Can't remember why, just that they aren't too desirable.
In all, great daily, parts are somewhat cheap. MPG for me is always between 18-19mpg on a 100% stock, 175k mile 4.0L.