If I take this message at face value and decide to switch to BitLocker, can someone answer this.

Dropbox + Truecrypt take full advantage of block sync & block encryption i.e. if a tiny piece of data is modified inside an encrypted container, only the relevant blocks are synced on update. Dropbox does not need to sync the entire container each time. This is a very useful feature. I know Google Drive & OneDrive aren't that smart.

Will bitlocker + Dropbox work the same way?