I settled an account I had at T-Mobile with them. It was a debt that was NOT past SOL for $452. I settled for $230 and it hasn't appeared on my CR since. I offered $200 and she countered with $230.
With all of my debts, except for US Dept. of Education, they disappeared as soon as they received payment. When I settled the account over the phone (from places that had already validated the debt and then asked for a faxed or mailed settlement letter), I made mention... innocent inquiry if they could maybe... possibly 
have the account show "Paid as agreed" instead of settled. They always said that they don't know how it will report and I let it rest - since I DID owe the money and it would be them doing me a favor. When I'd pull a credit report later, it would be gone entirely. 14 collection accounts -11 removed from dispute and/or refusal to validate and 3 settled and deleted entirely. And the student loan debt, which shows as Paid Collection. It's over 10 years old but it's the only history I have besides two auto loans I received 8 and 9 months ago. Two other student loans NEVER reported and I found them when I called to make sure there were no more... but there were. 
How careless I'd been that I don't remember taking out more than 1 student loan.
have the account show "Paid as agreed" instead of settled. They always said that they don't know how it will report and I let it rest - since I DID owe the money and it would be them doing me a favor. When I'd pull a credit report later, it would be gone entirely. 14 collection accounts -11 removed from dispute and/or refusal to validate and 3 settled and deleted entirely. And the student loan debt, which shows as Paid Collection. It's over 10 years old but it's the only history I have besides two auto loans I received 8 and 9 months ago. Two other student loans NEVER reported and I found them when I called to make sure there were no more... but there were. How careless I'd been that I don't remember taking out more than 1 student loan.Tangent - sorry. 
Plaza Associates settled very easily but make sure to get it in writing because it's hard to find someone who speaks English clearly. I had to be transferred 6 times and then call again because they had almost everything wrong on the letter. They'll try to get you to pay over the phone, saying that the "settlement will expire if you wait for us to send you a letter and you mail it back." So, I had them fax it to my employer and my wife sent in payment the next day, photocopied with the check and sent CMRRR.
Plaza Associates settled very easily but make sure to get it in writing because it's hard to find someone who speaks English clearly. I had to be transferred 6 times and then call again because they had almost everything wrong on the letter. They'll try to get you to pay over the phone, saying that the "settlement will expire if you wait for us to send you a letter and you mail it back." So, I had them fax it to my employer and my wife sent in payment the next day, photocopied with the check and sent CMRRR.