This isn't a feature that should be considered as an upgrade or a selling point to purchase a higher end product. It is foundational and fundamental. Not having this extremely basic functionality in the journal entry screen is a product DEFECT which should be corrected. Credits and debits must equal on a journal entry (clearly). Forcing customers to hand key totals off-system is simply outrageous. I have used numerous accounting systems over the years, and every one has this "feature" (if you can even call it that). 

To use another analogy, it would be like if McDonalds sold their basic cheeseburger with sand on the patty, and the only way to not eat a sandy burger is to pay more for the Big Mac.