Didn't realize you had kids.
That age it is important in my opinion that the kids have a place of their own. Making up a bed every night in the middle of the living area is a pain. It also restricts options for the adults.
I have seen a Jayco Jay Feather X213 which is only 300 lbs or so heavier than the X20E. It has bunks on the front wall, bath in the middle and a slide out king bed - head out behind the living area. Hate to suggest another trailer to look at, but I think it would suit your needs better - and give you a trailer which can grow with the kids.