My wife's cousin who lives north of Inverness (and has rarely ventured further south) also recommends Grant's.
I couldn't say whether or not MacSween's has reduced the quality because I haven't had any recently. We're postponing Burns Night until the weekend when we're all around to enjoy it together. (My mother-in-law is Scottish by birth but not exactly a staunch traditionalist. The rest of us only celebrate Burns Night cos we enjoy any excuse to eat haggis.)
d.