Thomas Shey
Legend
15 years ago, i would say - who cares about 30-40 minutes, let's talk it out, decide, agency is king. We played every week at least one 5-6 hour session and quite regularly another 3-4 hour session. Last 7-8 years, i would rather have DM hop in, use "force" to get things moving and actually play game since for most sessions i have hard cut off time, we play at best 25 sessions per year, sessions usually lasting 3-3.5h in total.
I also have to note that assuming in all cases it would only take 30-40 minutes would, IME, be optimistic. I've seen groups where that sort of discussion could be appallingly open-ended and/or end in no functional decision.

