... but your results may vary. I'll continue using it!
I too would agree. Results do vary. I can use the same rattle can on a small project and a week later having found a like item and to do the job again. Then looking at both rattle can painted some time later and notice differences.
It's humidity, overcast or not in the sunlight, outside temps, lite wind to no wind, time of day, and even barometric pressure all have a bit of play to all of this. Outside or in a garage, it doesn't matter.
Surface prep is a whole discussion in itself too to prevent rust coming thru, it's not just primer or primer+paint in one.
My neighbor with the Ford 1500 tractor is a union profession painter by trade. He has the knack over the 3 decades to know exactly how things would turn out before starting. From aircraft to masonry walls, he done it all. He has 2 garages. One has his mini paint booth. He has in the booth an air dryer and certain low heat lamps. He also has two IR lamps. There is a strung wire reams between two 6ft poles and a odd venting system. Even in his booth, he can tell the differences with what is controlled. As a professional, any rattle cans have to be within the same lot code, off the same store shelf from the same delivered box for the closest consistency.
He did paint his tractor the original Ford blue. Then he got the loader done. The loader was done week later. He had to wait for the same like weather day in a same like evening to do it in his garage paint booth. Yep, he's that picky. He writes all of the conditions down in a log book. I found it fascinating. About a year later, one of the loader cylinders needed to be replaced. Guess what, the replacement needed to be painted. He went to the log book and waited for the time to paint. The machine looks to NICE to use!
When he got the Ford 1500, it wasn't in good shape at all. It was missing the all the rear 3PT hardware too.