Hi Paul,
I've had an SSD C-drive for a little while. It is quicker to boot but so much depends on what's in startup. It's worth checking that in Task Manager - enter Startup in the W10 search box (in task bar if set). Any thing you are not sure about you can Google to get advice on what you can disable.
Without any software loaded W10-64 started in about 30 seconds!
My boot time is variable, why I don't know, at best it's 2.5 mins, worst about 3.5 mins. Except for overnight shutdown I set my PC to sleep wne not in use for more that an hour or so, it starts quickly then.
I have a calibration loader in startup and Task Manager says it has medium impact.
The screen appearance changes near the completion of the start-up.
Terry
From my experiences, it's like a day and night difference. While my boothing times were never that long as Paul's, they went down from like a minute to 10 seconds at most with an SSD.