I'm definitely not a paint expert. If the paint looks consistent and you can't see spray patterns, that's a good sign. On bad paint jobs you can see droplets.
There's also the question of durability, whether they use expensive and really hard epoxy top coat (the kind that straight up kills you if you dont wear the right kind of mask when spraying), or a cheaper one that will be softer and last less.
The risk around paint on seatpost is valid for all brands. Make sure you know your seatpost height to avoid pushing the post too low, scraping the paint, then pulling it up again, because that can look bad really fast.