First play through

I've only done the first mission and the park protest mission. So far, I am enjoying the game. It's pretty simple and straight forward but does require tactical thinking in order to use your characters effectively.

This is probably one of my favorite versions of Bunker. While my goal is still to get him into an optimal position for Turret Mode, I know I'm not going to stay in Turret mode the whole map, and so swtiching between his modes and deciding if starting him off in Operational or Turret Mode for optimum AP use is actually fun.

I kind of wish the other characters were like that. I actually haven't used Tachyon, Wraith, or my custom character's secondary stances much. The only reason to use them is if I'm fighting opponents weak to those damage types, but most of the time, it's better to use my ranged attacks. Maybe, it's just because I haven't played much of the game, but I kind of wish I had more motivation to switch stances like Bunker.

I tend to find there's an optimal stance for each character, barring damage type matchups. My custom character is good at drawing aggro, for instance, so I always want her to rush up and punch dudes instead of switching on her healing.

Also, I'm surprised you ever switch out of Turret Mode. XD The only reason I would is to reposition him!

There are heroes you get later on that have more incentive to switch stances.  But yeah, I tend to leave Wraith in Ranged Combat stance and Unity in Dinorobotics stance.  Tachyon is pretty similar in either stance, and I switch just for damage types.

I would leave Bunker in Operations mode more often if he wasn't so slow.  Grenade Launcher is great but I can almost never move him and use it in the same turn.

My hero is Companion/Interceptor, so I switch constantly with her.  Most times I swap to Companion at the start of her turn, create a Companion and make attacks, then switch to Interceptor when her turn ends because of its great Vigilance moves.