Barrelers is indeed a fun class and some dogs/handlers take to it really well.
I fill out the entries classes for Belle, my sister's beagle. Last year I only put her in a few times in Intro but she Qed twice.
This year in April was at games trial with no Intro, so Belle was entered Novice Barrelers and she Q both runs.
Since then just entered Novice since she had proved herself there.
She has Qed in Barrelers, I believe every Novice run this year, she just got O-BR-N this weekend.
Both Belle and my sister like the class and obviously they are good at it.
The title Q run is at following link if you want to see a recent Novice Barrelers course in action.