On CFW you can install Package Files (Pkg. files)
and on OFW you cannot.
Also you can run homebrew, emulators and backup copies from multiMAN on CFW.
On OFW you can only run legitimate games (physical discs).
CFW goes up to 3.55. OFW is in 4.00 right now
and soon to launch 4.01 OFW.
OFW is made by Sony. CFW by Kmeaw, Rebug, Rogero, etc.
True Blue grants you access to most of the 3.6+ games on CFW (games that require 3.6 and above firmwares),
whereas in Kmeaw you cannot play them.
Only a bunch of games have fixes for Kmeaw
(without a dongle).
I hope that clears out what are the differences
between the two.
[Edit] You can use Comgenie's Awesome Filemanager to copy games between your PS3 and any USB (FAT32)
connected external drives.
Check it out here:
I never used FTP to copy games from my PS3 to my PC,
but it is possible with the integrated file manager from multiMAN.
Also if you don't have a BD drive on your PS3, you cannot play certain games,
since they require to have a disc inside to launch them.
[Edit] By the way, you can simply use multiMAN (Games menu) and copy games
to a connected external HDD (FAT32) and multiMAN will automatically split the game files
if they are over 4gb in size. But you can read all about that in this thread:
Also a "Like" would be nice after all these explanations