RVs are a depreciating asset; you are going to lose money whether you trade it now or keep it a few more years. If the new unit fits your life style better better than the current and will make you trips easier and more enjoyable then it is worth considering. Enjoyment is the reason we typically get an RV in the first place.
Paul, Kathy, and Tux a 4 month Mini Schnauzer
2014 Tiffin Phaeton 42 LH, 2013 Honda CRV
"When the time comes to look back, make sure you'll like what you see"