I finally bought an SSD for my Mac mini. CamelCamelCamel notified me that my chosen SSD, the WD Blue 1TB 2.5”, had reached my price point so I went for it. It had a bonus 20% off, making the total price before sales tax about $170. Previous list price had been $260 and seems to be settling in at $230 at the moment.
I cloned it using Super Duper last night and it was ready this morning. Here’s the thing. This is fast. Logging in on my Mac mini with my internal hard drive was awful. Took forever. Booting from this SSD (still via a USB cable), login is blazingly fast. I expect this to get even faster once I take it off of USB and install it internally, connected via SATA III.
10 June 2018 Update: It’s been running fine over USB (holding Alt/Opt during boot to get a volume choice menu). So today I put it on the SATA bus, replacing the 1TB internal drive.