I am considering replacing a broken 17 inch MBPro with a 21 or 27 inch iMac, but I will need to be able to move the computer around the house/garden. Questions: 1. How fast is startup/shutdown times with the basic Fusion drive? 1A. With the SSD option? 2. Is it possible to install a "Deep Sleep" option so that the computer enters/exits deep sleep every time it goes to sleep? The reason I ask is so that I can unplug it and move it around without needing to reboot each time. 3. The SSD upgrade options are eye-watering, and the 21 inch is limited to 256/512GB for the non/retina versions (both too small). I was considering sticking a slim 1TB USB3 SSD external on the back of the iMac to use as a permanent data volume. Any comments on this? Is it be possible to sync such an external drive with DropBox? (essential). If I use "Deep Sleep" will it remount correctly? 4. What is the desktop performance of the 21 inch when using higher resolution scaled desktop options. I know that on the 27 inch, expose/and window rendering can get a little choppy - and that's with a dedicated GPU to help out. Note: I will NOT be playing any 3D games, but I do care about how smooth the desktop animations are.