I think there is advantage and disadvantage to both, as long as you know your options and what you are looking at, then you can make an informed decision for your situation.
Estate Sale does attract people, both the ones who want to purchase household items and collectibles as well as the ones who either want to have a lead for a house or are actually hoping to get the house before it comes on the market. You can also put words out there that the house will (or is) for sale in the near futhre. Perhaps the neighbors will bring buyers in.
You might want to think about how your parents house look with all their possessions in the house - does it look cluttered? unorganized,? Tired? Outdated? Are the possessions a plus or minus for the property? Is the house tastefully decorated with your parent's belongings, which will help the sale of the house? Do you want to keep some items for open house, or rather start fresh with an empty house and perhaps stage the house for sale? All these need to be considered.
As far as finding buyers are concerned. Do you have a price in mind and Realtor in place if you find a buyer during estate sale? Some people, unless stumbled upon the house during estate sale, who are thinking about getting a house during this time are usually thinking about getting a bargain. Is that what you are willing to do in exchange of getting house ready and formally putting it on the market?
I think both sets of answers are right, but you just have to decide which one fits your requirement better and go from there. But go ahead and find a reputable realtor to represent you - you will need that soon.