Really nice project! Thanks for your job!
It was installed on my machine as it is quite slow. However as soon as my machine swapped I could not use it for several minutes. I finally could look into it and found that many preload process where making the load increase very high... The default is to have up to 30 process to access concurently the same slow drive, while it is already used for swap, which makes the load go over 10 on my laptop everytime it needs swapping (which happens a lot as I have only 784MB and am running GNOME...)
There are no 4 star reviews.