Well, RTS (with the A* algorithm) is more of a brute force solution - it checks all possible solutions to the problem, then picks the shortest path.
Not quite - A* is a bit more clever than that. There are infinite unique journeys to travel between any points - just think of all the times you could go half way, go in a circle, then carry on, then the same with two loops round the circle, then the same with three loops round the circle...
So it's actually impossible to generate all possible solutions then pick the best. It's a surprisingly efficient algorithm, but as a tradeoff it is not perfect in all situations. But I think it picks the optimal path in 99.9% of situations or so. Worth it to get an answer before the end of the universe!
— - the RTS behavior generates a complete path in the 'Move to' action, stores it, then just starts moving the object along the already calculated path. So it's not actually running any pathfinding logic as the mouse moves around, so you'll see negligable CPU usage. The biggest problem with that system is if the path is really big and complicated, or you're moving hundreds of objects in one go, it could hang for a second or two while it calculates all the paths.