Among a few other things, it makes leveling up twice as fast as normal UP (apparently UL doubled the XP needed to level up), you gain two perk points per level, the amount of research data you get from schematics (which you need to craft others and upgrade workstations) is doubled, and the chance to upgrade items is changed to always 100%.
They’re not immaculate. They used to outright deny people the right to refund their games, but they turned that around after a massive lawsuit from a government agency. Good change! I support that. But they’re not behaving in an anti-competitive manner. What, are they supposed to intentionally make themselves worse in the hopes that other stores pop up? That’s not how any of this works.