With new rods today its all down to personal preferance (usually)
I prefer 1 piece becouse it seems to have a nicer bend/flex in the rod
Its super annoying sometimes when i wanna move it around and it scrapes my roof, i cant go fishing in my car and it can only fit in my truck box.
2 piece rods used to fall apart when u cast, but that was with old cheaper rods, shouldnt be like that anymore,
i decided to purchase the st croix triumph 4 piece travel rod during the fishing show to try out, seems to be quite nice, strong and hard to pull apart so i'm sure casting will be fine with it lol technology these days hahaha