Integrating Ops with AD is good and can go well installing as long as the AD tree is constructed properly. Ops can only search one folder in the AD, therefore all the whole AD enviroment will all need to sit in 1 OU and not the root directory, like most AD's.
Pro's:
1. Keeps the whole corp directory in sync
2. With integration to Ops and Speech server, you spend less time programming
Con's:
1. If the ops side is not kept upto date in terms of processing the detained users, it gets very messy
2. it can get complecated is the AD is not setup properly
3. you may find that the delete integration will not work, however, Mitel 3rd line is looking at this.