Dr. Tweedy has been our children's dentist since 2002. She's really calm and gentle, and I've appreciated that she always allows parents to hang out by the chair while their children are having examinations done.
Dr. Tweedy has been really good about letting me know what options I have, in terms of how often to get x-rays, whether my son should see an orthodontist now or wait, options for dealing with a very small cavity in a baby tooth. Speaking of x-rays, the last time we were in, they mentioned that they have a new x-ray that emits less of the dangerous stuff than traditional machines.
There's another dentist in the office who we've not seen--from observation alone, she seems pretty good, too.
March 2007 Update on my rating: I'd previously rated the practice as a little less than perfect, based on how staff in the office interacted with each other (not with kids). The past few times we've been in, the technicians/office staff have been super, much improved in their attitudes/professionalism.
Also, my son recently needed a very minor surgical procedure that he was incredibly anxious about - Dr. Tweedy worked magic in terms of gaining his trust and helping him manage his fear, and was able to complete the procedure without having to go to excessive lengths (i.e. the complete sedation that an oral surgeon had wanted to use). I highly recommend Dr. Tweedy.