Attended mainstream school most of my childhood. Till last 4 years as "High School" I finally go to Deaf school.
My experience about mainstreamed school. My education's pretty low when I attended mainstreamed school in RURAL (small town/country). Decided to transfer to other mainstreamed school in Big city, oh I loved it! Learned so quickly from education. Oh my, I survived with "Culture shock". Big difference between Rural and Big City about culture, education, people, more more.
About Deaf School, I decided join there for my high school (full four years). Still no regret for join there since. Deaf school helped boost my social life and self-esteem. Never forgot when I came to Deaf school on very first week, I used SEE/PSE and feel too offended by Deaf Culture. Finally use ASL after stayed there first few months. Yes, I was frustated with Deaf school but won't give up. Worth for me to have experience. Myself wonder what if I didn't join Deaf school for high school, then I might be VERY PASSIVE and limit social life for sure. Deaf258's right about smart street.
About Grammar, really *point* at the students for motivate in learning English grammar. I know some people have better English even graduated from Deaf School. Also, I met some Deafies have fair or lousy English Grammar even they attended and graduated from mainstreamed school. how odd!!! I do believe better English grammar is come from people's understanding and motivation. Even reading and family's concerning might help them, too.
Wanna better English grammar? then start developing ur motivate!!. I am, too I won't give up!