In my experience with CITI they did not sue in over 4 years and the amount stayed the same.Right around 12K They did not want to work with me as far as giving me break in amount or interest so I let it go. When I got sued by a CA,we went round and round as no validation, even though CITI was still the OC, although when I would call CITI said I needed to speak to the CA and would not give me any info.
I sued and got almost as much as they wanted, and then it went to another CA. I then decided to settle in full for a third of what they wanted and all was fine.
IMO CITI will sue does not sell or transfer their accounts and will have their ducks in a row, however if they had them there the first time I would not have been able to sue their first CA.
If it were me, I would WAIT as you will be able to negotiate a much better deal, and who knows you may end up far ahead, like me : )

Woofer