I have used these before - I designed them into some equipment at work. I used them as they were small, and self locate and securely clip in. As far as I remember, there were hard to crimp as each contact has to be pushed through individually. I think I started them with a pair of parallel pliers they pressed them in with the tips of snipe nose pliers.
If this is just for a hobby project - I wouldn't bother using it. I only used it on the project I was on as I was space constrained that that was the only one that would fit.
Neil