what are they both like compared too an xr400?
I'm fortunate enuf to own an xrr and an xr4- Maint is samesame between them, but that's about it.
The xr4 is fun in town, say, up to 50mph. At ~70 there's not much more.
The xrr, well... whack the throttle open at 70 and whump! yer going 90. Its just, beefier. Faster. Meaner. Heavier.
If I had to sell one it'd be the '4.