Dental school is what you make of it.
They don't cut corners but you can cut those corners if you want at any school. If I chose not to read the assigned readings and just learn enough to pass a test and forget it right afterwards, that's a choice to hurt your own education.
As far as clinical skills though, they were excellent. I'm still new in the field, but I'm shocked by what some other school grads can and cannot do or know. There are definitely schools that require more work clinically to graduate...Baylor dental students do an amazing # of crowns in order to graduate. But even clinical skills vary by the individual so vastly and numbers don't mean a whole lot. I had a recent grad tell me she had done 50 surgical extractions during school which i find to be an impressive # since I probably did just over half of that and did a lot more simple extractions. Yet at least once a day for a week she'd come find me in order to have me finish a surgical extraction she couldn't complete. The company I work for eventually let her go for other reasons. I recently had to recommend a student from an East Coast school be fired from employment as well. I observed and tried to help him for a week, but I was having to redo way to much of his work and after talking to other doctors with the company, this was how it had been for a while and he wasn't improving. I'm not even talking about particularly difficult things to do.
So, if you aren't a lazy person and really make an effort to learn and grow, it doesn't matter which school you choose, you can probably come out with great knowledge and skills, 3 years, 4 years, research school, clinical school, really doesn't matter that much.