I have been using Acanac for more than 10 years since they opened for business, till I moved to an area that TechSavvy is available besides Rogers. I never had a single bad experience with Acanac and their techs know what they are doing only if you could get hold of them, because they only solve user problems using emails. The quality of the phone line reps are not much better than that of Tim Hortons so don't expect them to know more than what you do as users.
Regarding TechSavvy, I have to hold the phone for 30min and up if I want to talk to one of their technical reps since they are so busy there, and I guess that is why Acanac choose solutions through emails.
Acanac also offers phone support. Like any other big company their techs range from complete idiots to some of the best in the business, depending on the luck of the draw. In general they are better than the e-mail support. I had similar experiences with Teksavvy's phone people, so I always handled my issues through their direct support subforum on DSL reports.
An unrelated note on DSL Internet installs: Nowadays, especially for higher speeds, they will typically send 2 techs.. A Bell tech who might only do work from the outside and might not even need to come up to your house, who makes sure signal comes to your house' demarcation point and a Bell subcontractor who will tell you he works for Acanac/Teksavvy/Velcom/Whichever company you ordered your service with, who will make sure the signal is OK from the demarcation point to at least one jack in your house. When I got my 25/7 line with Velcom, my reaction was "I didn't know Velcom had field techs.. WTG, nice touch" lol