lots to consider - when was it bottled is the best question. if it's a 20 year and just bottled last year, then i'd choose that one! if it's a 20 year, but was bottled 10 years ago, then well you have know how it has been stored all these years. is the seal intact? if it's been opened, i believe no matter how you store it, once that seal has been broken, changes occur. also, are you referring to the same brand of whisky?