When choosing a room air conditioner, is it better to buy spare capacity?

Would a 6,000 do a better cooling job although the running current would be a little higher than a 5,000? Like a six cylinder engine and a four. The work load is the same. But the 6,000 would have spare capacity.
Update: Present a/c is 5,000 and adequate especially when new. Room is 13.5 x 13.5.
Update 2: I think most of this advise applies more to larger sizes like 10k more more for a 9 x 12 room. I doubt a 6 ove a 5 would work that way. It gives it duty off time. (Everyone deserves a lil R n R, right?) But I think I will go with the 5k on the basis that the old one (5k) would well although not without its... show more I think most of this advise applies more to larger sizes like 10k more more for a 9 x 12 room. I doubt a 6 ove a 5 would work that way. It gives it duty off time. (Everyone deserves a lil R n R, right?)
But I think I will go with the 5k on the basis that the old one (5k) would well although not without its challenges, but a brand new one should take command of the situation. I know (you see) what an a/c should feel like. I have felt them.
8 answers 8