Ivas are actually only better than bankruptcy if you are not a home owner or have assets. There is money to be made from iva management and they are often encouraged to be a better option than bankruptcy. However as it's with cccs then it's likely they have considered whether bankruptcy would be better.
You need to be realistic with your budget as if you default the creditors can actually force bankruptcy.
Isn't more to do with whether the debt is secured against a property or unsecured? In my Dad's case he was a homeowner but didn't lose the house with an IVA because the debt was all unsecured. If made bankrupt he would have lost the house.
My DH currently has an IVA and CCCS have been really helpful thoughout. We are home owners and the IVA has not affected that. Our income recently dropped dramatically and CCCS re negotiated the terms of the IVA so we are now paying less per month.The budget they have drawn up for us is also very fair, for example our budget for food shopping per month is £430.00 for four of us (me, DH and two young dc's).