Sumburgh got a CAT I ILS i believe with it's extention. Gets you down to 300 feet, not that that'll help when the haar is tearing through on the deck at 50knots! And didn't this summer.
Scatsta does seem to miss some of the worst weather but suffers from not having a cross runway. Feeding the helis with passengers is hard if the planes can't land because of the cross wind. The facilities currently available are pretty limited, not even a VOR at Scatsta just the NDB and primary radar for SRAs. Not ideal, but does seem to manage.