Read here: https://bitcoin.org/en/release/v0.15.0#multi-wallet-support
You don't need to maintain multiple copies of the blockchain!
Thanks, I definitely going to take a look.
I was thinking about having two 100% different Bitcoin QT to minimize risk of messing up one of the wallets... (as I'm a novice with the app, the only thing I know is the "-datadir shortcut option" and always migrated the entire data directory from here and there).
But this makes sense because you can save 150GBs of data.
Edit: For now I've stopped using that registry "strDataDir" and started using a shortcut with -datadir= flag (with a new path).
I don't like the idea of having a registry key showing where is there data directory. I prefer a shortcut on an external hard drive.