Buying Advice, 21.5" or 27" iMac?

[FroggyTaco]

I suspect my most used apps are cached when in sleep so ready to go in an instant. However, the real world slowdown must be my NAS and an SSD would not assist there.

However, for my business needs an ability to have my data on my own closed cloud is far more important than having the Data locally on my iMac.

Totally agree with that. You could some day utilize a DAS if you ever wanted faster speeds. Especially since storage HDD is already so cheap & SSD seems to be in freefall these days.