I have a '14 274BH, and it has been great. Bought it slightly used in 16, and have about 5000 miles on it so far.
Like you the first thing I did was replaced all the incandescent with LED. On mine the control panel that has the tank and battery levels and pump/heater switches also has the awning retract/extend switch and the strip light. The LED light on the awning one would think the light switch would be right next to the extend/retract switch as well.
Keep the roof clean and UV protected, check the seams and caulking, and wash the sides a couple times a year as well as a good wax at least once a year and that will keep the interior from having issues down the road.
About the only thing inside that you want to be watchful of is the side of the dinette that is in the open. It is weak and the corner tends to be pulled on, and people stretching against the back will weaken it more. This is probably true on all of them, so if it wiggles, get some of those angle brackets, both the flat face and corner type and screw them into the corners. Stiffens the seat right up .
That is pretty much all I found with mine, have nothing bad to say about it. Everything else is just common upgrades that would have been done regardless of brand or model.
Today I just got mine out of the barn and finally installed the Strongarms I bought in 2017! What a difference! No more wiggle, feels nice and solid.