Each different shape and size of trailer has its own advantages and disadvantages. Finding the right type of trailer for your purposes can be a very challenging task. You need to try and estimate how much use the trailer will be getting and what type of terrain it is most likely to be going over. It could be a better idea to invest in a good offroad trailer right from the start.
Good offroad trailers are much more rugged and sturdy than onroad trailers. They can handle a much wider variety of terrain without getting stuck where any onroad trailer would be forced to fly the white flag of defeat. This means that those beautiful, remote campsites you have always wanted to take a holiday at are now accessible and you do not have to worry about limiting how much luggage your wife and daughters can take along (we all know how much stuff women seem to need to pack for a trip!).
What about that cross country trip you have been wanting to take? Imagine being able to drive from Cape Town to Cairo, just because you can! This is where an offroad trailer would also come in handy. Many African countries' roads are in a terrible state (if they even exist anymore) making it impossible to traverse in anything other than a 4x4. This means that a regular onroad trailer just will not cope, however, you definitely need to have a trailer to transport all your equipment, food and fuel. An offroad trailer will be able to handle the terrain that a 4x4 will drag it over and the rather severe beating it will receive from the surface of the road (although it may be an insult to roads elsewhere to dignify them with this title).
We have established that an offroad trailer will go where no onroad trailer would manage, but what about areas that an onroad trailer will do just fine in? I suppose that if you have no sense of adventure and have decided to spend the rest of your life in the concrete jungle where the only dangers are the occasional pothole and taxi driver, then an onroad trailer will do you just fine. Naturally, an offroad trailer would be able to handle any task put before an onroad trailer. Truem they are a little heavier than an onroad trailer due to the extra reinforcement, but they work just as well as an onroad trailer.
Also, because the offroad trailer is a hardier vehicle than the onroad trailer, regular use will not damage it as much. This means that you should save money on repairs as you will be doing them less often. With proper care, the offroad trailer should also last a good while longer than an onroad trailer due to its rugged construction.
An offroad trailer can do anything an onroad trailer can do and many things it cannot. So why not save yourself the hassle and just get an offroad trailer from the get go. That way you do not have to invest in a new trailer if you decide to go where few others go and your onroad trailer will not manage the terrain. You will save money on repairs and be able to take everything you anticipate needing on your cross country trip!