Common RPM rates, in both laptop and desktops, are between 5400 and 7200 RPM. Given two identically designed hard drives with the same areal densities, a 7200 RPM drive will deliver data about
33% faster than the 5400 RPM. Using the HDD to act as system drive, running applications from it that care about latency, 7200 RPM is a noticable difference when the drive is running the operating
system and opening programs.
Unfortunately, there is no option to upgrade to a 7200 drive on the 21.5" display iMAC. I can't explain why Apple insists on making this three legged turtle their default storage option for the 21.5" It's like driving a golf cart on the freeway. Eventually, you're going to get to the destination, but no one is gonna enjoy the experience.
So you decide to stay within your budget before configuring your new iMAC, and out of necessity, you go with hybrid storage 1TB on a 5400 RPM spinning hard drive where the only paired option on the 21.5" display is 32GB SS flash. Basically, it's the experience as you had before, except instead of driving a golf cart, you've now upgraded to the Toyota Prius. So by the game rules that Apple writes, you're forced to max out to future proof an iMAC selection by upgrading to a 27" that you may not want. Or you can take the alternative option by staying with the 21.5" and upgrade to a 512GB SSD drive. Either way, plunking down $1800 for either option may just seem obscenely over priced for an aging system.
Many other manufacturers don't default their hard drive design at this ancient RPM rate. What benefit does anyone receive owning a 21.5" iMAC? Nobody can defend the argument by saying iMAC will last
longer than all other manufacturer's PC's or that Apple has the greatest customer service. No, Apple doesn't want to lower their starting price on this aging system because they had all the angles
figured out long ago.
Their bottom line profit margin by charging full price on an older system should drive away the average
educated consumer in that market. But I guess there are more technology challenged consumers out there that Apple would care to admit they have managed to pursuade. If all it takes is to manage converting believers to think that every product released is the top of line line and state of the art, then they've won.