Engine time is logged by the tach. Lots of ways to log everything else, but engine is by tach. If you don't have a tach, then you can use any system you can defend!
It is misleading to use personal experience as the norm. When leasing aeroplanes the lessor has normally charged on tacho hours as its the least likely to be fiddled and therefore required maintenance to follow that. Having owned and operated my own flying club/school and aeroplanes for in excess of 30 years I have otherwise never used the tacho for maintenance although I acknowledge that many owners/operators do.