[Help] Need help comparing Vectors

Unity Engine
1

So i got a Scripts which checks the start and end position of moving Platforms. Now i want those platforms to turn around when they hit the end position, but dont really now how to check at what time that state is reached because I dont know yet if the x, y or z coordinates are higher or lower compared to the startPos.
Does anyone have an idea how i could handle this or how i have to think about this? Im quite new to c# and unity…

Here is the Script, I first tried to check when pos.x>=startPoint.x+=dis.x and so one, but i never know if it will be <= or >=…

using UnityEngine;
using System.Collections;

public class MovePlatform : MonoBehaviour {

    public Vector3 startPoint;
    public Vector3 endPoint;
    public float speed = 1;

    private Vector3 pos;
    private Vector3 dis;
    private Vector3 moveV;
    private bool turned=false;
    private float distance;


    void Start () {
        pos = startPoint;
        this.transform.position = pos;

        dis = endPoint - startPoint;
        distance = Mathf.Sqrt((dis.x * dis.x) + (dis.y * dis.y) + (dis.z * dis.z));

        moveV.x = (dis.x / distance) * speed * Time.deltaTime;
        moveV.y = (dis.y / distance) * speed * Time.deltaTime;
        moveV.z = (dis.z / distance) * speed * Time.deltaTime;
    }
  

    void Update () {
        pos = this.transform.position;
        if (turned == false) pos += moveV;
        else if (turned == true) pos -= moveV;
        this.transform.position = pos;
    }

}
2

Just use Vector3.MoveTowards instead of doing it manually.