While the core of both tools is similar (both following Ackerman's principle - accounting for the vehicle's turning characteristics and the trajectory influenced by speed), the algorithms differ for each tool.
SmartPath tool: In the SmartPath tool, the vehicle trajectory usually involves a transition section (a spiral is required to get from the initial steering position to the steering needed to make the turn) and an arc section (a circular section once the steering has reached the angle needed to make the turn).
Intellipath tool: Intellipath generates the movement by making small but constant changes to the steering which could result in a constant spiral; ie the vehicle's trajectory describes a spiral, similar to the transition in the SmartPath tools. Both transitions are influenced by speed, since the spiral is a function of the rate of change of lateral acceleration.