B.C.
I can't tell you if this is a good deal or not for your area.
However you can tell if it is a good deal by looking on your last bill and seeing how much per KWH you were charged.
Then go to the web site of the new company and see how much the new company is going to charge you.
Unfortunately the reason the people in charge of this decision (city government) may have other reasons for giving the contract to Constellation and it may be in their best interests, not yours.
I'm on the water board of directors for a small water district and I'm amazed at the reasons they do things. I ran for office because they passed higher rates and didn't seem to care about us rate payers. I've been working to reduce the rates and no one but me wants to rebate money to the rate payers. They want to find different ways of spending any savings.
Good luck to you and yours.