Hi
If the cache has been emptied it won't load instantly from the vpj file. A lot depends on the length of the project and the number and format of the clips and the editing but it will be longer than from a cache that has the files already there.
A test here with an old (slow) Vista machine and starting with an empty cache, fully loaded a 30 minute project with 91 HD clips into VP in 14 minutes 12 seconds. The CPU ran at around 55% The cache was 217 GB and held 546 Video files and 273 sound files.
Saving this as a vpj file and then reloading VP, the VPJ file loaded the project fully in .. 38 seconds
The cache was now emptied of all files...
The project was loaded fully back again using the vpj file...This time it took 13 minutes 36 seconds with the CPU running around 65%
Obviously keeping the cache full is pretty beneficial!
Nat