Normally I'd say that Income Protection is better than Critical Illness cover because it covers more possible causes.
In your situation, they are comparable. The Canada Life Income Protection will only cover you if you are very badly incapacitated. You can get Permanent & Total Disability cover as an add-on to many Critical Illness policies. They're not the same thing but they're not far apart either.
Other differences - Income Protection premium qualifies for full tax relief; critical illness doesn't. Critical Illness pays out a lump sum; IP pays an ongoing income.
The Income Protection probably covers you for marginally more possibilities than a Critical Illness policy with Permanent and Total Disability cover.