I have abandoned my GC processing in US and moved to Canada in 2013
Compared to US ,there are very few IT jobs in Canada.Canada has 3 to 4 Major cities which have IT Jobs ,whereas US has over 30 to 40 cities for IT Jobs
Salary: 30 to 45% less pay and over 60% less ,if you take into account the USD/CAD conversion and taxes
Cost of living may be more in Canada (Toronto,Vancouver or wherever IT jobs exists.But if you take into account free health care over Health Insurance expenses for a family,then cost of living will be almost same
A IT professional with around 10+ yrs exp may get around $80k to $120k (1 CAD= 0.76 USD) .i.e around $60k USD to $90k USD before taxes.Average tax bracket above $80k is 26% to 29% federal and 12% Provincial
Entry level IT Jobs (3 to 6 yrs exp) are very hard to get into and pay very less ($35 k to $50k)
IT Jobs in Canada are very few and competition is high.90% of them are not advertised and get filled through internal references
Coming to lifestyle:It is more or less similar to US,but you will not get good deals or varied shopping choices .The prices are usually 15 to 30% higher than US
The major advantage is you don't have to worry about H1-B/Visa headaches or maintaining status