Re: [JacobG] Flat or Pro Pack?
The terms "flat pack" and "pro pack" are fairly misleading when applied to BASE pack jobs. It's probably better to refer to a "pro-stack" or (in my experience even less confusing) just call them "over the shoulder" or "on the ground."
There should be no functional difference in the outcome of the pack job, no matter what method you use.
It's really a question of personal comfort (and ease).
In my experience, new jumpers have an easier time visualizing (and controlling) the canopy if it's laid out on the ground and packed there, so I generally teach an "on the ground" method to students.
It's not that packing on the ground makes a "neater" or "better" pack job. It's that it is easier for a specific jumper to make the pack job "neater" or "easier."