So "Yes" the system has changed, and "Yes", we don't call "Rent to Own" anymore.
For your second question nope: if you pay 15 (or 100 months) and want to leave AND own the latest version (at the moment you are leaving), you would still have to pay 49$. As a reminder, you previously had to pay during 18 months to get a major version of the product, meaning if you started paying for SP1, you would have SP1 at the end of your 18 months of payment (even if SP2 was out). This one of the reason we changed it: when/if you leave, you have the option to get the latest version.