Phill, I made a sample capx to play around with the easing issue, and too me it appears that having a high acceleration and deceleration on the pathfinding behavior gets rid of any visible easing effect. I had to slow the timescale of the game waaaaay down to see the easing effect when I set the acceleration and decelerations to 99999.
If you download my sample, and look at the second enemy (Enemy2) you should see its speed jump from 0 to 200, and then come to an immediate stop at the end.
You can use the "Time Scale Factor" slider to adjust the game's time scale. Drag it down towards 0% for "slo-mo". If you drag it ALL the way down, you can barely see the speed on Enemy2 increase up to 200.
Take a look and let me know if that helps.