There is of course a downside to the auction route.

Because the drop of the ausctioneers hammer denotes exchange of contracts, its the sellers responsibility to provide most if not ALL of the pre contract documentation. Some of these costs can be written into the conditions of sale as being untimately the responsibility of the buyer and can be added to the sale price. BUT, if it doesn't sell you will still have all the solicitors and auctioneers fees to pay and no sale.

Private sale will be much less stressfull.