Hi Dbond,
It's good that you are able to get settlement deals at just half the price. The time span for negative info to be on your credit report starts from the time you were late for the first time or from the date the account went into collections. Mostly it stays for 7 years, no matter its negative or positive.
Even after payment also the negative listing will appear, inclusive of late payments, accounts the creditor turned over to the CA and filed judgments against you. However, the original creditor or the credit bureaus have the right to remove the negative listing. Charge-offs are injurious to your credit so it's better to contact the creditors beforehand.
If you are late due to certain ups and downs, but finally pay off the amount being a good customer, then out of goodwill, you can request the creditor or collection agency to remove the negative listing. So you can send a Goodwill Letter for removing the old negative item from your credit report.