We have the Bighorn 3585RL, which is the same basic floor plan as the Landmark Grand Canyon.
There is also the Big Country 3450TS with the same floor plan.
Although ours is a 2011, they remain basically the same.
The differences, besides the name is in the fluff.
Nicer furniture, larger window by the dining table, all stainless appliances, fancier woodwork and more for the Grand Canyon.
I don't think the Bighorn comes in full body paint.
You would have to do a side by side comparison to see the differences.
You will like the storage cabinets in the hall slide going to the bedroom.
There is only one tight spot between the bed and bath wall and the bathroom is a bit small for me, but in any RV there will be compromises.
That was ours as we like the large bedroom slide with the extra cabinets, the grand staircase and the downstairs floor plan.
Have you called the Landmark sales team to find out if there is one at a dealer closer than 5 hours?
Might be worth the call.
Peace
Dave