I am 15 and my parents used both at different times and I have thoughts.
Bark felt way less invasive. I knew it was there but I did not feel like every text I sent was being read by my parents. That mattered a lot. When it flagged something, my mom came to me and asked how I was doing rather than confronting me with a screenshot. That was the right move and honestly it made me more open to talking.
Aura was more noticeable. The location tracking pinged every time I moved basically and my dad kept asking where I was going when I had already told him. It created friction over nothing.
The screen time limits on Aura were also kind of frustrating in ways that felt arbitrary. Like being cut off mid-homework because gaming apps count the same as school apps in certain configurations. That got fixed eventually but it took a few weeks of arguing.
What I think actually matters: if parents are going to use these things, talk to your kid first. Seriously. I knew kids who found out by accident and it damaged things at home for a long time.
Also the idea that monitoring replaces trust is wrong. Monitoring because you trust but want to be a safety net is different from monitoring because you do not trust. Teens can tell the difference even if they cannot explain it.