For regular Springbank, a portion of the wash is distilled three times, and a portion of the wash is distilled twice.
Hence, at the end of the day, it is commonly accepted that Springbank adopts a "two and a half times" distillation.
When they make Longrow, they adopt a more conventional double distillation.
I don't dislike the current 100 proof (10yo) - it's actually a very acceptable malt, but I don't think it stands head and shoulders above anything. Put it this way....it's not the whisky on which Springbank earned its reputation.
Same goes for the 15yo. Pleasant & acceptable, but nothing exceptional.