IMO, the Fuji system is perfect in a mechanical sense. There is not one improvement I could really think to add. No dust, no light leaks, way less user error (if any at all), and they are extremely lightweight and fast. Making duplicate exposures is a breeze, without having to be super careful to knock your rickety cameras out of place when flipping the film holders. If you are shooting a lot of sheets on one project, they are great.
The drawbacks are the price and the limited selection of emulsions. One of the Pro 160 films is not available at all in Quickloads. I can't remember whether it is C or S...probably C. (It will be a very sad day for me when they discontinue 64T in Quickloads.) Given the price, I really try to pick them up past date 50% off specials from my local shops, and have done well this way so far. Also, I generally make fewer duplicate exposures, if any at all...but then again, the reasons for my making duplicate exposures in the first place (possible light leaks, dust, damage, user error) are all but eliminated by the Quickload system.
In my opinion, if you can afford it, and you can do what you want to do using the available emulsions, it is well worth it.
I really wish Ilford had a system that is just as good, as I prefer HP5 and FP4 to anything Fuji has. Quickloads are the only way I use Fuji b/w film, although Fuji is my preferred color film.