Homax (the main brand aerosol texturing compound) is very touchy stuff. Changes in temperature or the pressure of the propellant in the can radically affect the texture you get. This means: a) always do a test coat on cardboard before using it; just because you got the nozzle adjusted properly yesterday doesn’t mean you will get the same texture on the same setting today; b) because of all the test coats you make, don’t expect to get anywhere near the patching coverage advertised on the can, c) you’ll have to throw out the can before it’s empty, because it will get to the stage where pressure is ramping down so fast that you can’t get consistent results even on a small patch.
All the above said, it’s still much cheaper to texture your own patches than to pay someone else to do it.
The water-based texturing compound is to be preferred. Not only does it stink far less, it dries slower. If you get a nasty surprise, it can be scraped off before it dries with relative ease.
Premixed mud is easier to use than trying to get all the lumps out of some powder you have to mix with water.
That said, there’s reasons to fiddle with the powder. For openers, quick-setting “hot mud” is only available in powder form. I just bought a bag of it to do the last two patches in my house. Reason: they’re high up, and I had to rent a large step ladder to reach them. Thus, the bother of mixing my own and the expense of buying another kind of mud (when I still have plenty of premixed left) pays for itself because I’ll be able to return the ladder far earlier.
Hot mud is quick-setting but not quick-drying. I.e. when it first sets it will still be damp, and you won’t be able to sand it without your sandpaper quickly clogging. It still takes 24 to 36 hours for hot mud to dry. The solution is to use a drywall knife or paint scraper to shave excess mud off. Save sanding for the final step, after it’s all dry.
Be sure the mud you buy has the words “lite,” “light,” or “easy sanding” in it, particularly if it’s hot mud (which is notorious for setting up as hard as a rock otherwise).
Hot mud comes in various set times, from 5 minutes up to 90 or more. I chose 45 as a compromise between being able to mix it and work with it without feeling rushed and rapid turnaround for the next stage.
To the best of my knowledge, hot mud is only available in ridiculously large batches. I had to buy 18 lbs of powder, of which I will use only a fraction. (But, to reiterate, that expense still paid for itself.)