Exactly. I've seen people who always do `tar xzvf` and have no idea removing the `v` is the correct way to make it not print the name of every file in the archive.
I use the -v switch since I want to see what I decompress, however I didn't knew that I could supress the z switch.
Isn't it better though to omit the -v switch and do `ls *` and/or `tree` afterwards? That gives you the same information but structured so it's much easier to understand.
The advantage of -v is that you can see what is being extracted as it happens. This is useful if you have a tarball with thousands of small files, as otherwise it's hard to tell whether tar has got stuck or there are just a lot of files.
You didn't use to be able to suppress the 'z' switch. You had to specify 'z' or 'j' depending on whether you wanted gzip or bzip2 decompression. It's a somewhat recent (sometime in the last 15 years, I think) change to "tar" to make it just detect the compression algorithm.