Recently I bought a new laptop to meet a need for mobility.  L8 installed fine and thankfully it runs very well.  One concern I had for the new machine was for an adequate SSD capacity since my desktop machine has consumed nearly 68 GB.  The laptop had more space left after installing L8 than I expected.  A nice surprise!  This made me curious and I found:
Desktop           67.9 GB           7,741 files in 173 folders        Resources: 3,137
Laptop             33.4 GB           5,120 files in 159 folders        Resources: 3,131
Why such a difference?  I know 6 small PB's aren't on the new machine.  The Data and Document sub-folders are essentially half size in the new laptop install.  Has the desktop install just gotten bloated with useless garbage?  Should it be cleaned up by uninstalling / re-install to reclaim needed space on the hard drive?
Thoughts anyone?