Given that the SSD is now an integral part of the M1's SoC design, it's no surprise that application loading times are extremely rapid, though the speed difference between this and today's standalone m.2 SSDs is minimal. We'd have expected the M1's extra efficiency to translate to lower power consumption. Strangely, the M1 is rated at a maximum 150w continuous power draw, which is the same as the old Intel Core-i5 Mac Mini. Naturally, the M1's power efficiency is less evident than in the M1 MacBook Air and Pro, as of course battery life isn't an issue with the Mini. To all intents and purposes, the M1 is a silent computer.
Even when continuously running hugely intensive benchmarking software, you'll need to have your ear pressed against the casing to hear the internal cooling fan running.
The first thing that strikes you about the Mini M1 is how impressively quiet it is.