I have had my 21.5 inch iMac for 1.5 weeks, and it is the base $1299 model, with a 1TB Hard Drive. But, now I am trying to decide if I should return it to buy a new one with an SSD. I know that hard drives are slow, and the iMac lags behind my early 2013 15 inch retina MacBook Pro in terms of responsiveness (upgrading to new 13 inch retina MacBook Pro within a month). So, I have until November 10 to return. If I do, I think I will go for 256GB Flash Storage. I really did want it to begin with, but shipping times back then were just a little too slow. Thoughts? Should I keep or return?