They are, in fact, too good to be true. Our water heater stopped working on a Saturday, so we looked up Calgary plumbers that came out on the weekend. We saw that Mr. Mike's did, and charged only (according to their website) $49.99 to come out + an hourly rate. A Mr. Mike's guy came out, spent a while in our basement (though not apparently unscrewing anything), and informed us we'd need a new water heater. He then gave us (an extremely high) estimate for one. And then we got the bill: a little over $400 (for telling us it was broken, which we'd already surmised since we had no hot water). The guy did not, as the invoice itself said, actually do anything except take out a flashlight and visually look over our broken water heater. The invoice also included an environmental fee for $30, although it's unclear what kind of disposal ops are required for clicking on a flashlight.
But here's the kicker: they offered to lower the bill when I called to complain. . . if I agreed to sign a waiver agree "not to leave any negative reviews about Mr. Mike's Plumbing on any social media platforms." So apparently you can get a discount on the ruinously high fees for their services but only if you sign an NDA. I suspect this might be one reason there are so few negative reviews about this company.
Our view of the company is that they lure you in with the promise of cheap rates, charge a mint, and then prevent anyone from posting negative reviews. For all I know, their work might be decent (we didn't go with them for the water heater replacement since we found another plumber who charged about half what they did), but they seem excessively pricey and engage in what I find to be sleazy business practices.