Weight balance, its important to know your 'real tongue weight' once all loaded up. That under the bed storage is usually large and sometimes we tend to over load it with heavy items.
The position of the TT door is just as important and it usually goes hand in hand with the bedroom location. Rear BR, front door.
Keep in mind , the location of your hookups, you want to be able to park close enough to the pedestal at the same time, not be on top of another RV that's parked behind you.
Also consider the position of the picnic table fire ring and where you will park your TV (Tow Veh) . A rear door TT will cause you to walk around and through your own campsite in order to access your TV. I keep a lot of stuff in my TV and i'm constantly in/out of it.
Personally, i like a front LR - front door because it feels like home rather than a TT. I also want my tv to be directly in front of the sofa. Some floorplans force you to view the tv off to the side at a 90 degree angle. That gets old real fast .