I had a manual balloon press- Used the heck out of it when we had 4 major hurricanes in 14 months. I can say for sure, beyond the shadow of a doubt, the quality is not nearly as good as even the cheap autos. It is very important to have the same volume of air in each balloon printed. If the balloons are different sizes when printing the print will show in different places when you inflate them all the way. Also print speed and consistant pressure is critical. In many ways it is easier than shirt. In many ways it is harder.
We do get much better detail on balloons than shirts. I can print at an 85 line screen for balloons. At the fine of a dot some of the ink is lost between the weave of a shirt.
I'm just sayin'
Matt