A quality orchestra with reasonably priced performances as far as these things go. They really have something going pretty much every week, which is impressive. They try to spice things up a bit with video projections and imported guests sometimes. Post show discussions with the performers in the lobby are a nice touch. Even if you don't know your Brahms from your Beethoven, they have plenty of special performances throughout the the year that are more contemporary, like the music of Star Wars, or The Motown Sound. Yes, you can dress up, but as this is Calgary you can go in a nice pair of jeans too. :-)
The main complaint is not about the orchestra, but their typical venue, the Jack Singer Concert Hall. Getting around during intermission is a bit of a madhouse unless you're at orchestra level, and even then, the bathrooms and concessions are overwhelmed.