I would no sooner put melamine on an exterior application than I would a fine silk. The material is not capable of performing adequately under that application. Besides the fact that I can't imagine trying to install melamine panels on the side of your house.
Hey, it's your house, do what you want. I think you would do better to explore hardiplank, or another product made specifically for exterior siding.
The thing is, siding has to withstand multiple cycles of: hot-cold wet-dry hot&wet-hot&dry cold&wet-cold&dry
These combinations are true just about anywhere you live, and the material has to be capable of dealing with the thermal expansion and contraction associated with the temperature fluxuations, as well as an ability to repel water without absorbing it and either rotting or simply delaminating and falling apart.
Melamine scratches easily, is hard to repair, and is not intended for exterior applications. As a material, it works well for cabinets and furniture, but it sucks around water. Literally.
Okay? Those are my thoughts. I doubt you will find many people who have experience with this because it shouldn't be done.
If you really don't believe me, go ahead and buy a sheet of melamine, lean it against your house or fence and let it sit there for a year. Then you'll have an idea of what it will do on your house. Keep in mind, siding "should" last for 15-20 years or more. Especially with as much labor as it is to replace it.
Not trying to be mean or anything, I'm just saying it won't work.