Unsure about others, but I notice the most significant time drain by running Timers.app (Apple made).
If I run timers on my iPhone, no problem, the alert to the Watch causes no abnormal drain. If I use the Apple Watch to run the timer, significant drain. I use them in the morning to monitor multiple activities while doing a routine.
Why is a "Timer.app" such a battery hog? Is it because it is part of the "double tap" screen that has live activities.. I'm going to try and remove the live timer activity and see if it helps, but yeah, 10.6 seems to drain faster than 10.5.x