Just got a flyer in the mail for this deal today. Seems like a good deal at first but once you crunch the numbers, I'm not sure if it's worth the hassle. Based on my last three years consumption history (I have variable rates), I should be able to save at least $110 to $120 bucks with the ATCO deal. But as others have noted, roughly only one-third of my natural gas and electricity bill is for the actual commodity itself. The other two-thirds are all the associated fees. So if ATCO charges higher delivery fees, it will eat into those savings pretty quickly. And you also have to factor in the potential time lost and inconvenience if there are any problems with the switch from Enmax to ATCO.
Also, if I was to apply the savings to 2015 to 2017, it works out to be roughly 4% savings on my overall annual bill, although the 2017 number is estimated as I do not have my November or December bills yet. But for those who do not want to crunch the numbers, a quick and dirty way to calculate your potential savings is to apply a 4% discount to your annual utility spend.