Our 320RLDS has a very different floor plan, but I see some similarities and will comment on those. TW on the 2009 RLS is shown as 1055. Count on around 1300# after you fill the A frame, put some stuff in the underneath compartments (I can't see them in floorplans but mine are both in the front) and pack your clothes in the wardrobes and overhead cabinets. I'd suggest a Class IV or V hitch. You'll need a good weight distribution hitch (WD hitch).
You've got over a ton of payload capacity (weight of stuff you put in it) so your actual on-the-road weight will be considerably higher than listed dry weight of about 7400#. You don't mention your tow vehicle or size of family that will be in it. Those answers to those two items can be unimportant or quite important, depending.
Your driver side chair in the living area will have to be moved to the passenger side in order to close the slide. Check to see if changing the bed sheets would be difficult for the changer.
The quality of our 2011 has been very good, with zero serious defects and just three very minor ones being fixed at Camping World right now, as we near the end of our warranty. Make every effort to learn its history.
I used 2010 specs and 2009 floorplan in this answer. Hope this helps a bit, and whatever you end up with, ENJOY CAMPING!
'11 Eagle 320RLDS
'02 F350 PSD Dually 4WD
DW's Ride, '13 Expedition
'14 Denali XL