I am looking for a watch that can display my performance on a route compared to a previous run.
Basically the watch needs GPS to store the route with times and when I am next running that route, it can figure out if I am ahead or behind.

Does a watch exist with such a feature? I don't want speed at any point of the route since I am not going to know what it was the previous time.
Ideally it can store details for a minimum of 3 routes.

My TomTom Runner 2 can do that (there are newer TomToms mines a couple of years old). Choose a previous run, then race yourself - it shows you how far ahead or behind you are in metres. Like racing your ghost.

I'm sure garmin etc probably can do similar.

I don't have a specific recomendation, but this site is good for reviews of fitness gadgets and is probably worth reading the reviews when you have narrowed your choice a bit.
https://www.dcrainmaker.com/

Regards
Hugh

Does it have to be a watch and is it for running on your feet?

If it's for driving and lap times perhaps theres a phone app making use of the phones GPS system.

Yes, running using my own feet. Not taking phone when running.