You probably won't find a better opinion on SJ than what Terry Pluto wrote for The Plain Dealer...
QUOTE
The Browns wisely declined to tag safety Sean Jones a "franchise" player, meaning he'd be paid about $6.3 million. Instead, he will be a free agent at the end of the month. The more I watch Jones, the less I know about him -- other than he seems very average. When healthy, he's a strong tackler against the run. But he had knee surgery early last season, missing four games and that seemed to cost him mobility. He never was an asset on pass coverage. After four seasons and 60 games with the Browns, is there any reason to think Jones will be anything more than just OK? How much salary cap do you commit to Jones? In my mind, not a lot.
The biggest argument in favor of keeping Jones is the Browns have no one else to take his spot. In 2007, he was on the field for 98 percent of the snaps. He played every game in his first three seasons, before 2008. He is reliable and a solid locker-room guy. But the safety combination of Jones and Brodney Pool was nearly as much of a problem in the secondary as young cornerbacks Eric Wright and Brandon McDonald last season. They certainly didn't seem to give those kids on the corner a lot of help -- and Jones has especially been vulnerable defending tight ends over the years.