It all depends on the amount of maintainence effort expended, how much it is used, and where it is used/ stored.
Our trailer is 10 years old this year, gets used 8 months out of the year including fulltime living for 3 -4 of those months, sits outside for 9 months and inside a barn for 3 months, but it still looks new inside and out. Everything works as it should and there are no water leaks.
The above is possible because we purchased a quality product to begin with and have been very careful and persistant in maintaining the rig. I would not trade our trailer for any of the newer rigs out there. Instead, I look for ways to keep it current and up to date. Pride of ownership goes a long way in being satisfied with the rig you have, in my opinion.
Purchase a decent rig and maintain it well and you should be fine with almost any brand.
Barney