I always purchase the cover for my grills and smokers as it is one more layer of defense against the elements.  In addition to routine cleaning and a light coat of oil, the cover is essential.  Not to sound preachy, but if you are going to spend your hard earned money to make a quality purchase in this level of unit, keep it protected and add years to your investment.  My friends cannot believe how many years and cooks I have on my Offset CharGriller Smokin' Champ...because I  take care of it and keep it covered. Just my two cents. It's your money.