High Motor should be renamed "aggression". With it on players show less patience and a desire to get in on the play. I've found that players make better decisions when it is off. At the very least, I'm turning it off for HB, FB, TE & OL. I've left it on for WR as I want to see them go after the ball. I really don't know if you can see this, but so far it seems to play out good.
On defense definitely turn it off for LB, except 3-4 OLB pass rushers. It gives a boost to DE and DT, so I only use it on those rated 85+. I went with 85+ as I'm using 30XP so drafted players aren't likely to get much past 85.
I left it at default (whatever a player is set to) for DB as on occasion I'll see them be overly aggressive and try and jump a route. Occasionally they are successful, but also they will at times miss and give up a big play.
One other approach on offense is to have it on for rookies and 1 year players (especially OL) as it causes them to be aggressive blocking and not always hold their position for a delayed rusher. I think this can be seen as reflecting the lack of awareness and discipline that young players come into the league with.
The nice thing about traits is that when you change them, they seemingly have no affect on CFM actions. They don't resigning, depth chart position or any other area that I can tell. They do, however, affect gameplay.
Thanks for the interest. I'm going into week 5 with the Cowboys and I've had a bevy of games. 2 close hard fought games and 1 easy win due to injuries and turnovers and 1 blowout. I've had a number of minor injuries. In game 3 I lost my starting C for 5 weeks and was forced to reorganize my OL. My 80 RT got owned by JPP, forcing me to adjust my game plan and blocking scheme. I've struggled to run and have been run on. Good QBs have done well, while lower rated ones have struggled. I'm really liking the way its playing out and all without adjusting gameplay sliders.