Hands down JJ is a better game day corner with the better on field talent.
Trumaine Johnson did not have a good season last year. His play down the stretch was just about average for an NFL starting corner. Trumaine was not the best playing Ram DB on the field the last 4 games of the 2016 season. IMO he was outplayed by Mo Alexander & Blake Countess. Not what you want to see when this Ram Org, will have utilized a near 31 million of cap funds to retain for the 2016/2017 seasons.
From a distance I believe that Tru is far better team player than JJ. In addition I think that Tru is much better locker room guy & a better person overall. I expect Tru to fit in well with this new Wade D & play much better this season. However I do not see Trumaine being here after this season. He will move on to a team who can afford to pay him a big paycheck the Rams will not be in this position.
Bottom Line I am far more interested in how Snead /McVay/ Wade plan to find future starting DB's who can replace all of our 2018 DB free agents like .... Trumaine Johnson, Lamarcus Joyner, Mo Alexander, Cody Davis, EJ Gaines, Nickell Robey-Coleman & Troy Hill. I was seriously surprised in this draft to see ZERO corners selected in a very big corner draft year:shocking:.I would expect Wade to use this season to weed out this corner unit & focus on new blood from the 2018 draft that helps greatly with the near future cap issues on this team. It would not surprise me that next season all but one of the 7 listed above DB's are departed.