The Experior (formerly known as Block) test has changed from the six hour 150 que.s to a four hour 100 que.s test. On the Master there is more about commercial calculations, motors, and Chapters 5 through 8.
Yes, there are questions about community cable systems, etc. I suggest that you take the residential and after passing it then take the Master. Many of the questions on the master are the same as on the residential.
I've been using Experior/Block to license electricans here since 1985. Although I already had a local license I took the test in 2000. I consider it a good credential that is recognized by many jurisdictions.
I used the Code-Electrical bookstore material to prepare for the test.
Good Luck. Alan
If it was easy, anyone could do it.