Like DrAzzy mentioned it's a real pain in the butt if you choose a connector that requires crimping pins.
I can only say that if you know how to crimp and you have done it enough times it becomes second nature and is not much of an inconvenience UNLESS you have A LOT wires to do and then it can be pretty tedious. I wouldn't wish it on a newbie but I think calling it a "pain in the ass" is a very subjective statement. It does however require having the CORRECT crimper for it to work. I have done hundreds of crimps with no problem but in all honesty it is not fair to use my personal experience as an example because I have been a technician for over 30 years. I do understand that for some people it truly is a "pain in the ass".