I always play on Expert, I find it to be the most balanced. On master I simply find it too tedious. Yes killing things might be a bit harder because of less damage by you on master but if you could win the fight on expert, you would still win on master. I find it less realistic to play on master.
Sword and board work fine on Legendary. I use minimal crafting; I only smith items for myself, or improve items I intend to sell. The character's level is in the low teens, but those first few levels were very difficult. Lately the combat reminds me of master difficulty, but it just takes longer. Legendary difficutly should've been handled differently,e.g. raising the level of the enemy encountered overall, greater numbers of enemy, higher prices, hardcore mode, etc.
I have been thining about playing an adept ironman character. I will have to make sure that I don't get too powerful, and instead gain perks in skills that I have overlooked in the past. It may make an interesting play-through.
Depending on the build either Expert or Master. I play to have a reasonable challenge but still enjoy myself - Master is often tedious especially on builds with limited defensive power in early levels. Might start jacking it up to Legendary once I hit the late 30's, that's usually when I start to get bored.
I'm glad to see I'm not the only person to play on anything less than Master difficulty. Expert is my benchmark as I find it a comfortable challenge at early levels - a time when I may not have the resources for a long fight.
Once character dependant perks and equipment start falling into place at around level 20, I'll ramp up the difficulty to Master for the rest of that toon's life.
I generally stick to master difficulty,but it is rather annoying because unless whatever character I'm playing starts with decent defense/a way to keep enemies off of me,I run into problems with certain enemies,boss type enemies with two-handed weapons,in paticular,hitting me once and then killcaming me before I can react. I think I'll be sticking to expert from now on when I start,then switching to master/legendary as my character gets strong enough to deal with it.
That's a good strategy. I find the game gets easier with perks, and raising the slider at levels 20 and 40 keeps things fresh without getting too difficult too early.
That said I mostly play adept. I don't usually play optimized characters and if I want an exercise in digital self-flagellation I'll play Dark Souls.