My child does not go to St. Josephs, but I know a lot of people who have sent or are currently sending their kids there. It is right across the street from my home. I can tell you that based on the people I know, if your child is average - no learning disabilities - then it's a fabulous school. It is safe, well-rounded, and grounded in faith, morals, and values. However, I know a family who has two children with ADHD and the school could not provide the attention the children need to learn. They ended up pulling their children out and moving them to public school. On the other hand, I know a family who put their two oldest children through St. Josephs, but put their youngest through the public school right across the street - Emerson. They had trouble with all the second language families that were impacting the education their child received. I also know several families who have raised their children at St. Josephs and have sent their kids to private Catholic schools, specifically Mater Dei. Their kids are amazing...successful, well-rounded, and faithful!
On a personal note, my child goes to Emerson as I believe in public schools for a variety of reasons. I am very happy there and love what the school has to offer. I feel safe and like that the school feels like a family. However, I would not hesitate to send my child to St. Josephs. I'm sure it would be a wonderful school for your two little ones.
Sorry I could not provide personal experience there, but I thought it would be better to send some feedback rather than none at all. St. Joseph has a wonderful reputation!!! Good luck with your decision.