We have an 8ft lq with a toliet and shower, there is enough room to shut the door to use the toliet but not much more, the shower is tight but usable.  I was in a trailer last week that was also an 8 ft lq, larger shower and a bit more room in the bathroom but it certainly made a difference in the amount of living space.  Obviously with only 8ft to work with a bathroom that is 12-18 inches larger can make a big impact.

Given your choice would you prefer a larger bathroom or a bit more living space?  For me I am glad we have the extra living space as this is where most of our time is spent.