Catholic priests actually receive college training in counseling. Also, anything that is told to a Catholic priest is confidential, i.e., they won't rat you out to your parents or use something you confessed against you. Confession can be done behind a screen so the priest doesn't even know who you are. And it's not a committee of priests, just one priest on the other side of the screen.
The biggest difference is this: JW elders are looking for things you've done so they can punish you. With a Catholic priest, his belief is that all sin is against God and that, when a person sins, he is distancing himself from God. The priest's goal is to help you heal the rift with God and build you up spiritually. That's why, almost always, your "penance" for sins is to say various prayers, to help you draw closer to God. For the Cathoic priest, it's not about punishing the sinner; it's about healing the sinner and helping them to stop sinning. For the JW elder, it's not about the person's relationship with God; it's about controlling the members and keeping them in line with the WTS.