I have covered all my trailers. My last trailer I had for 9 years and the exterior looked like new. You do need to cover the gutters and any sharp edges with something, I use foam pipe insulation. You need to also keep the cover tight so it does not move. I have covered my current trailer for over 3 years. I buy the cheapest cover I can find because they all will all rip. I spend about $300 on a cover that last me about 9 years, with some rips. I strongly recommend a cover. If you can keep your decals, roof and other components not exposed to the sun and weather for 5 months out of the year, Nov-Mar for us, it is well worth it.
2012 Cedar Creek Silverback 29RE
2011 GMC 2500HD Diesel