I did the Rustoleum paint job on our LeMons car and it was an absolute nightmare. By the time you get the paint thin enough to spray in a regular 'automotive gun', it required several coats just to get coverage. (didn't help we were going from black to white!)
But the paint takes foreeeeever to dry, and that dust gets everywhere and stays sticky for days. we also had cars outside when I painted the thing, and cars 150' away still had to be clayed and buffed to get rid of the leftovers carried by the wind.
There is also a lot more labor involved in getting a rustoleum paint job to look good-- so much labor that I would rather pay $300 for a gallon of paint and do it in a weekend vs. $30/gallon and take 3 weekends!