Had them on the bike when I bought it.
1- They were the small ones and were too small for my use.
2- The opening on these was very small, therefore making it hard to get stuff inside.
3- They are waterproof!
4- You can lock them with a key
5- You can put them on and take them off in as much time as you can get the key in the ignition, it's that easy.
6- The brackets are not bulky and the bike looks really nice when the bags are off.
Like I said they were the small ones, I am sure the bigger ones have a half decent opening.