I couldn't find an 05 "Reiler" - I know I have a few, but I can't put my hands on them. Anyway, I tried a "regular" WG Spatlese from 2005 and I do agree in part with what you are saying. It's not completely closed, but I do find it out of balance right now. It's not as aromatic as I think it should be but it's not completely muted either. The sweetness seems to be the primary impression. I feel some acidity, but it seems to be separate from the wine and more evident in the "aftertaste" rather than integrated.
I will also say that I've always found the "Reiler" to be the "broadest" of the wines - I like it, but I get more of an impression of a late fall apple rather than an early Honeycrisp.
I think you will find the wine a lot more complete and expressive in several more years. But as Daniel has said a number of times - He's only been making his own wine (commercially) since 2000, so who knows? I guess all we have to go on are his neighbors, and extrapolating to his style.
