"I would stay away from the Mac Mini."
I realize this is an old topic, but I can NOT let this go by.
You clearly have a defective mini. Nothing you claim is normal. I currently have Photos, Safari, Thunderbird, iTunes, Xcode and OneNote running while typing this reply. This is on the same mini as you have (had?) - 2014, 8GB, 2.6gHz i5. It is even running from an external USB 3, 1 TB HD. It is fast, responsive and no spinning disks.
When running from the internal 500 GB SSD, of course it is MUCH faster. The internal SSD has Sierra, the external HD has High Sierra.
There is no reason AT ALL to "stay away from the Mac Mini". It works as well as any other PC with an i5 and 8GB. With a SSD it is VERY fast, again just like any other PC. 4 open tabs in Safari is NOT beyond its capability, any more than 4 open tabs in IE is too much for Windows to handle.
In short, your post is total baloney.