I personally love using slide film but it can be tricky sometimes which is why I don't use it so often. Slide film or colour reversal film refers to a film that will give you a colour positive. This is great, as I can already see what I have got, once the film is developed. With black and white or colour negative film there is a lot of guessing involved and you basically need a contact sheet to determine what is what. But with slide film you already have an image in your hand which is great.
What makes slide film so great is that it produces amazing colours. They are crips and contrasty and have that extra pop to them. So when I know it will be very light outside and I am focusing on colour at the moment I will use slide film.
There are a few downsides though. It is pretty pricey and I can't develop it in my dark room. The process is kind of complicated and involves a lot of nasty chemicals so I have steered clear of developing it on my own so far. Another negative factor is that slide film is just not very forgiving. You don't have the same range of exposure with slide film as you would have with black and white or even colour negative film. Therefore it needs to be just right. And another thing, slide film doesn't like low light conditions either. Of course rules can be broken but I think in this case, slide film is just not your friend for situations where light is sparse.