Is not using tanking stances actually best?

[Chrono_Rising]

The answer is difficult without getting really specific. In general this question breaks down to two parts.

Part 1: Trash pulls. This is healer dependent, but if being out of tank stance will cost your healer GCDs to heal you then it is probably not worth it to drop tank stance. This is because healers generally have better aoe than tanks. However, if being out of tank stance doesn't cost your healer any GCD's then it is a win win for both of you to output as much as possible. Generally people aren't talking about trash pulls when talking about being out of tank stance.

Part 2: Bosses. This is what people are usually talking about when discussing this topic. In dungeons, there isn't a single boss which requires me to heal with a GCD provided people do mechanics and the tank pops cooldowns at appropriate times. There is no benefit to the tank being in tank stance in this case, I'm not losing GCDs because healers have really powerful oGCD heals to keep tanks topped. I'm not a healer main, but this is very easy to accomplish when I do runs on healers.

Savage isn't really different, but to heal without using a GCD does take some planning, but it is also possible in a number of turns. This does takes planning and coordination. In general, taking more damage being out of tank stance doesn't directly translate to using 20% more healing GCDs, especially if people work together to keep damage down. Things like feint/addle/etc. exist to help with busters and mitigate fluff damage.

However, this all assumes a number of things: like your healer is actually doing dps and isn't pure healing and people playing their class optimally. Ultimately the questions will come down to how comfortable is your team with using their tools and how much do you gain while minimizing how much your healer loses. 25% penalty in tank stance is a lot of lost dps, but if your healer takes a 90% penalty when you are out of tank stance then this is clearly some things should be discussed.