Paul Kuharsky (and others) have done some good reporting on the most obvious battle in camp: the kicker battle. In a recent column, Kuharsky said,
Between the end of offensive drives in team period and additional kicks in full team work, Travis Coons hit from 41, 39, 42 and 47 yards and missed left from 49. Maikon Bonani made from 33, 39 and 47, pulling a kick from 43 badly left and also missing slightly left from 42. It’s early to panic, but it was not a great kicking evening.
Which I think is the correct way to put this. There is still a lot of time left before the Titans have to decide which kicker they prefer, and even then it is likely that the other player won't be lured away by another team.
If I had to make a decision on who the kicker was going to be at this point, I would have to go with Travis Coons. Coons has been much more accurate, and while Bonani has a huge leg I think Coons might not be noticeably weaker. Bonani seems to be so focused on adding distance to his kicks, that it often screws up his accuracy. If the Titans need to pick a player that they can rely on for 16 games and not one long field goal, it has to be Coons.