I doubt there are problems inherent to the 8312S that can't be found in any other trailer from any other brand.
You need to be realistic (and this is a hot topic for some). Every trailer will have problems and you need to expect that minor problems will occur with your trailer.
If buying new, a good dealer will catch these issues and correct them when they accept delivery from the factory but before they deliver to you.
You can mitigate problems with a trailer by working with a dealer that has a good reputation for service in your area and by completing a lengthy and thorough review (PDI) BEFORE you take possession.
If buying used, it is incumbent on you to do all of this. You really need to be somewhat mechanically inclined and informed in order to spot issues and, later, to be able to work on your own trailer. This is also important as I am convinced that some problems (not all) are due to neglect or not knowing what needs to be done (e.g., regular and proper roof maintenance).
Sometimes, you WILL find a lemon of a trailer. Unfortunately, there is no coverage under state lemon laws for most RVs. Trailer forums will be chock full of these stories because they, like FRF, tend to be focused on problem solving. This can make it seem that ALL trailers will have major problems, but that is just not true. I believe most campers do not have major issues, but we just don't hear about it.
DW, 3 Kids and our Goldens
2012 Shamrock 233S
2008 Toyota Sequoia 5.7L 4WD