Actually the IXD2 comes with the FuMO-29 by default, which just sweeps 20 degrees in front of the sub. You can upgrade to FuMO-30 pretty quickly. I find it picks up ships just outside of visual range, so certainly not as good as the US radar and reading it yourself is certainly not as nice as the US radar scope.
For air contacts etc., the radar detector (i.e. FuMB) is probably a better friend
And yea, German radar was definitely ways behind the US radar. That was probably the fleet boats' greatest advantage. Mind you, in the game we're probably better supplied with radar right now than the real U-boats were. Most of the monsoon boats didn't have any radar at all.