Trimesters for High School, Middle School, Alt. Ed. & CTE

We are doing some preliminary investigating and I could use some information from any of you who have the experience in implementing trimesters. Questions:
How long have you had it in place?
Do you see a positive correlation to academic achievement?
Has it cost you ($$-wise)and if yes, when (what year) did the cost increase become most apparent?
Have any of you who have gone to trimesters then gone back to semesters?
How has the community "bought in"?
Your overall experience in implementing: positive or negative AND how long did it take you to implement?

THANK YOU!!!!!!
Brooke Ballee
bballee@vanburenschools.net