Well, i enjoyed caster. And played only with her.
Guessing each time and trying to memorize the attack patterns is a bit fun. I think it also changes per floor.
You can see the monsters so I don't need to worry of accidentally running into them. Some pathways and spawnrate are good enough for easy grinding. I've only got very few instances of standing around doing nothing in a dungeon. Most of the route includes all the highest tier monsters on that floor, though usually it's on the second floors.
I haven't tried archer and saber, only caster and as female. I like how caster flirts with mc, but at the same time not, because I played as female and it seems like the lines are the same for male, though I'm not sure, I recall her saying something like husband.
It's also my first Fate type game but I watched Fate/Zero. I like anime so the talking part is fine with me.