101 is a lot of tunes for the money - good value and a great, varied selection. It means most are quite short - just the main themes, but that's ok. For example, for Mozart Symphony 40, you're only getting one page of highlight melodies as opposed to a full movement or a dedicated arrangement over many pages. Which is fine if you want breadth over depth. All suited for solo playing, no "rest for 8 bars" sections.
I'm playing on a flugelhorn (beginner level) and all themes are arranged in easy ranges, nothing higher than the occasional A-above-the-stave and no weird key signatures.