CBC version: The alien refers to "bags of mostly water". Troi exclaims, "That's us!"
Chosen version: Data pedantically explains that humans are mostly water.
CBC: on decloaking, Picard says to the Romulan captain, "I'll be making a full report on this incident to my command. I imagine you will do the same."
Chosen: Picard sends a message that his report will be made to both commands.
The Nth Degree:
CBC: on decoupling from the computer, Bradley turns back into his previous uncertain self. Troi and Crusher look at each other with regret that he was no longer the masterful male.
Chosen: Bradley keeps his new-found confidence and solves a chess game as he exits.
These are the differences I remember clearly - I suspect there are others.
In all these cases, the CBC version is better theater, more memorable. One would expect that it was an official licensed release. It seems that the Chosen collection contains edits prior to the final one. If so, the tapes may have been collected by someone involved with the production rather than being the final releases.