Is it possible to plant 105 acres of soybeans in 13 hours with an 8-row, split row planter? It is if you can refill the planter in 10 minutes, and the seed is available to you as often as you need it.
I accomplished this feat, which I'm sure many others have as well, because when I was low on seed, technology, aka a cell phone, let my partner know I would need seed at a certain time. The bean buggy pulled up the first time just as one of the rows on the monitor readout beeped and dropped to zero, indicating it was out of seed. Two people doing fill-up for 16, 3-unit boxes makes it go even faster, but just having the seed available to convey into the planter instead of having to dump it in via 50 pound bags is a time-saver. One person can run the seed-buggy almost as quickly.
If you have a semi-efficient bulk system, say a converted-gravity bed wagon and it takes 30 minutes to fill up vs. 15 minutes with a new rig with all the bells and whistles, that's an hour of savings in a full day for the upgraded tender if you fill up four times. An hour of time can mean an extra 8 to 9 acres planted.
Seedsmen say the trend is definitely going to bulk soybean seed, and that it won't go back to 50 pound bags. In fact, the first darling of bulk, the 2,000 pound sacks, are giving way to boxes, which are in turn giving way to straight bulk form the supplier into the seed tender. This requires having a big enough tender to hold a reasonable amount of seed. Many of the newer tenders can hold boxes of more than one variety at a time, giving flexibility on variety. Other tenders have split compartments so that you can carry two varieties on the tender at the same time. That increases flexibility.
Fifty-pound sacks were part of the 'good old days.' Don't expect them to return unless drastic changes take place in the industry. A few people may still use them, but only in isolated instances.