Of course I believe in them, almost all of them because the reason behind it why so many other altcoins that has been created is because it does a thing what Bitcoin doesn't do or offers. It is just that Bitcoin is the pioneer or the first crypto currency that is why it is so famous and widespread and hold the number one spot compare to other crypto currency coins.

Everything has its own advantages and disadvantages if you may say, just do some research in trusting a single coin because nothing beats your instinct within a thing. If you will just rely on others opinion it is up to you but at the end it will be frustrating if something bad happens.