First what year? is it new or used?
If new, I would also touch bases with Thunder RV in LaGrande OR
Second (if used) you know there are three floor-plans and lengths that vary over the model years.
The current 27-5L is actually over 30 ft and has both slides on the driver side. From 2012 to about 2000 the 27-5L was about 29 ft long with the main slide on the drivers and the bedroom slide on the passenger. Older then that there was only one slide it the rig was 28 or 29 ft.
2008 F350SD V10 with an 2012 Arctic Fox 29-5E
When someone tells you to buy the same rig they own, listen, they might be right. When they tell you to buy a different rig then they own, really pay attention, they probably know something you don't.