I personally prefer the look of open sights on single actions by a wide margin. As you said, with adjustables they just look chunky. To me, they wreck the gun's smooth flowing lines.
Actually the older sights are adjustable for windage, which you probably know, but I think of them as fixed also. I agree, I think they look better than the the adjustable ones found on most of the new models. The adjustable ones are probably better for shooting, I'll admit but I look at my guns a lot more than I shoot them.