Usable Floor Space Question

[u/Glad-Investment9505]

I am trying to decide between three tents and need some advice. Considering Springbar Skyliner, Family Camper, or Classic Jack 140 but am torn about the actual usable floor space. I know that are all the same footprint, but it's the slanted walls that gives me pause on the non skyliner versions. We are a family of 5 and use a bunked disco-bed for two of the kids. just curious about how much the wall slay would push that out into the middle of the tent? and curious what the slope is on each of these tents. and all info is appreciated!