For pro-looking-amateur fans.
We're never sure if fans of amateur look for well-shot early footage of cute babes they may already be familiar with, or the bust-out amateur with attendant bad camerawork and sometimes-boring action. Totally Amateur 21 is an example of the former, as the fine camerawork is offset by the fact that Monti, Crystal Knight and Macy are well familiar to the porn-watching crowd.
The best scene has Macy hiking with Arnold Schwarzenpecker in the forest. Arnold's been gone for several years, so you can guess how early in her career this scene was shot. He spreads out a picnic blanket, then engages Macy in 69, cowgirl and reverse, doggie and horsie style fucking.
A promised strap-on scene never materializes, nor does a promised "Brazilian couple."