The abruptness can be adjusted by changing the "Boat Scale". See "sticky" thread "Minn Kota I Pilot Questions and Answers" - about page 50-51.
Basically the trolling motor/I Pilot thinks your boat is bigger and heavier than it is and is using more energy to pull you back to your spot.
Now, the issue of how far Spot Lock ranges, thats another issue discussed in detail in that same thread.
Hope this helps.
*sorry, just noticed you already adnusted boat scale*