I've travelled a lot. Yes, it's a mediocre airline compared to world standards. Here are some tips to make for a better experience:
Book directly with Air Canada for the best experience and not through third parties. Third parties don't release the booking to AC until your travel has begun. By then it may be too late to make any changes.
Become an Aeroplan member (or whatever their new points card will be) so all your details are readily available, and the experience is improved.
They still have mishaps, all airlines do, and someone will always have a bad experience. Hopefully it's not always you.
And lastly, don't take it out on the airline staff. They are only the messengers doing the best they can while dealing with problematic people all day and night...literally. They are human too. If they have a good experience with you they will do their best to make you comfortable.
If you have a complaint deal with it in a letter or email when you land or when you get home. Get names and numbers of managers and senior staff on the plane and make a formal complaint. My experience is that they do respond.
At the end of the day it's means to an end, not your final destination. Be on the ready and open to everything. It always makes for a good story over dinner with friends.